diff --git a/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.spec.ts b/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.spec.ts
index 75ccf300cf1..b624c7734ff 100644
--- a/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.spec.ts
+++ b/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.spec.ts
@@ -23,6 +23,7 @@ import {
   dimKeyFromDimValues,
   dimKeyFromRow,
 } from "../../../dashboards/pivot/pivot-click-selection";
+import { buildExpandKey } from "../../../dashboards/pivot/pivot-expand-keys";
 import { createPivotClickToFilter } from "./pivot-click-to-filter";
 import { ExpressionFilterManager } from "@rilldata/web-common/features/dashboards/filters/ExpressionFilterManager.svelte.ts";
 import type { MetricsViewsProvider } from "@rilldata/web-common/features/metrics-views/providers/MetricsViewsProvider.svelte.ts";
@@ -64,6 +65,11 @@ function dk(dims: Record<string, string | null>, order: string[]): string {
   return dimKeyFromDimValues(dims, order);
 }
 
+/** TanStack row id as PivotTable's getRowId builds it: the values from the root to the row. */
+function rowId(...values: (string | null)[]): string {
+  return buildExpandKey(values);
+}
+
 /** A real filter manager over {@link PIVOT_METRICS_INIT}, torn down after the test. */
 function createFilterManager() {
   const { value, destroy } = createInEffectRoot(() => {
@@ -247,10 +253,15 @@ describe("flat table: single-cell-per-row", () => {
   it("replaces existing cell in the same row", () => {
     const { result } = setup(config, data);
 
-    result.handleCellClickToFilter("0", "country", false, data[0]);
+    result.handleCellClickToFilter(
+      rowId("US", "NYC"),
+      "country",
+      false,
+      data[0],
+    );
     expect(sel(result).isCellSelected(dkRow0, "country")).toBe(true);
 
-    result.handleCellClickToFilter("0", "city", false, data[0]);
+    result.handleCellClickToFilter(rowId("US", "NYC"), "city", false, data[0]);
     expect(sel(result).isCellSelected(dkRow0, "country")).toBe(false);
     expect(sel(result).isCellSelected(dkRow0, "city")).toBe(true);
     expect(sel(result).cellSelections.size).toBe(1);
@@ -261,8 +272,18 @@ describe("flat table: single-cell-per-row", () => {
   it("deselects by re-clicking the same cell", () => {
     const { result } = setup(config, data);
 
-    result.handleCellClickToFilter("0", "country", false, data[0]);
-    result.handleCellClickToFilter("0", "country", false, data[0]);
+    result.handleCellClickToFilter(
+      rowId("US", "NYC"),
+      "country",
+      false,
+      data[0],
+    );
+    result.handleCellClickToFilter(
+      rowId("US", "NYC"),
+      "country",
+      false,
+      data[0],
+    );
     expect(sel(result).cellSelections.size).toBe(0);
 
     result.destroy();
@@ -271,8 +292,18 @@ describe("flat table: single-cell-per-row", () => {
   it("allows selections across different rows", () => {
     const { result } = setup(config, data);
 
-    result.handleCellClickToFilter("0", "country", false, data[0]);
-    result.handleCellClickToFilter("1", "country", false, data[1]);
+    result.handleCellClickToFilter(
+      rowId("US", "NYC"),
+      "country",
+      false,
+      data[0],
+    );
+    result.handleCellClickToFilter(
+      rowId("UK", "London"),
+      "country",
+      false,
+      data[1],
+    );
 
     expect(sel(result).isCellSelected(dkRow0, "country")).toBe(true);
     expect(sel(result).isCellSelected(dkRow1, "country")).toBe(true);
@@ -299,8 +330,13 @@ describe("nested table: multi-select", () => {
   it("allows multiple cells in the same row", () => {
     const { result } = setup(config, data);
 
-    result.handleCellClickToFilter("1", "revenue", false, data[0]);
-    result.handleCellClickToFilter("1", "other_measure", false, data[0]);
+    result.handleCellClickToFilter(rowId("US"), "revenue", false, data[0]);
+    result.handleCellClickToFilter(
+      rowId("US"),
+      "other_measure",
+      false,
+      data[0],
+    );
 
     expect(sel(result).isCellSelected(dkRow0, "revenue")).toBe(true);
     expect(sel(result).isCellSelected(dkRow0, "other_measure")).toBe(true);
@@ -341,7 +377,12 @@ describe("nested table: cross-parent selection isolation", () => {
   it("does NOT select X under B when clicking X under A", () => {
     const { result } = setup(config, data);
 
-    result.handleCellClickToFilter("1.0", "revenue", false, innerRowXUnderA);
+    result.handleCellClickToFilter(
+      rowId("A", "X"),
+      "revenue",
+      false,
+      innerRowXUnderA,
+    );
 
     expect(
       sel(result).isCellSelected(
@@ -363,7 +404,12 @@ describe("nested table: cross-parent selection isolation", () => {
   it("does NOT select row header X under B when clicking X under A", () => {
     const { result } = setup(config, data);
 
-    result.handleCellClickToFilter("1.0", "outer", true, innerRowXUnderA);
+    result.handleCellClickToFilter(
+      rowId("A", "X"),
+      "outer",
+      true,
+      innerRowXUnderA,
+    );
 
     expect(
       sel(result).isRowHeaderSelected(dk({ outer: "A", inner: "X" }, dims)),
@@ -391,7 +437,7 @@ describe("null dimension values", () => {
   it("selects a cell with null dimension value", () => {
     const { result, fm } = setup(config, data);
 
-    result.handleCellClickToFilter("0", "total", false, data[0]);
+    result.handleCellClickToFilter(rowId(null), "total", false, data[0]);
     expect(sel(result).isCellSelected(dkNull, "total")).toBe(true);
     expect(selectedValues(fm, "country")).toEqual([null]);
 
@@ -401,8 +447,8 @@ describe("null dimension values", () => {
   it("deselects a cell with null dimension value", () => {
     const { result, fm } = setup(config, data);
 
-    result.handleCellClickToFilter("0", "total", false, data[0]);
-    result.handleCellClickToFilter("0", "total", false, data[0]);
+    result.handleCellClickToFilter(rowId(null), "total", false, data[0]);
+    result.handleCellClickToFilter(rowId(null), "total", false, data[0]);
 
     expect(sel(result).cellSelections.size).toBe(0);
     expect(selectedValues(fm, "country")).toEqual([]);
@@ -443,7 +489,7 @@ describe("selection survives sorting", () => {
     );
 
     const usDk = dimKeyFromRow(dataBefore[0], ["country"]);
-    result.handleCellClickToFilter("0", "total", false, dataBefore[0]);
+    result.handleCellClickToFilter(rowId("US"), "total", false, dataBefore[0]);
     expect(sel(result).isCellSelected(usDk, "total")).toBe(true);
 
     // Simulate sort: UK now first
@@ -630,15 +676,15 @@ describe("deselect retains shared column filters", () => {
 
     const { result, fm } = setup(config, data, columnDimensionAxes);
 
-    result.handleCellClickToFilter("1", colId, false, data[0]);
-    result.handleCellClickToFilter("2", colId, false, data[1]);
+    result.handleCellClickToFilter(rowId("New York"), colId, false, data[0]);
+    result.handleCellClickToFilter(rowId("Bronx"), colId, false, data[1]);
 
     const dkNY = dimKeyFromRow(data[0], ["borough"]);
     const dkBronx = dimKeyFromRow(data[1], ["borough"]);
     expect(sel(result).isCellSelected(dkNY, colId)).toBe(true);
     expect(sel(result).isCellSelected(dkBronx, colId)).toBe(true);
 
-    result.handleCellClickToFilter("2", colId, false, data[1]);
+    result.handleCellClickToFilter(rowId("Bronx"), colId, false, data[1]);
 
     expect(sel(result).isCellSelected(dkBronx, colId)).toBe(false);
     expect(sel(result).isCellSelected(dkNY, colId)).toBe(true);
@@ -679,7 +725,7 @@ describe("unrelated global filters are left alone", () => {
   it("does not re-add global filter values when selecting a cell", () => {
     const { result, fm } = setup(flatConfig, flatData, {}, globalFilter);
 
-    result.handleCellClickToFilter("0", "revenue", false, flatData[0]);
+    result.handleCellClickToFilter(rowId("US"), "revenue", false, flatData[0]);
 
     expect(selectedValues(fm, "country")).toEqual(["US"]);
     expectGlobalFilterIntact(fm);
@@ -695,7 +741,7 @@ describe("unrelated global filters are left alone", () => {
       globalFilter,
     );
 
-    result.handleCellClickToFilter("0", "revenue", false, flatData[0]);
+    result.handleCellClickToFilter(rowId("US"), "revenue", false, flatData[0]);
 
     expect([...get(selfFilteredDimensions)]).toEqual(["country"]);
 
@@ -705,8 +751,8 @@ describe("unrelated global filters are left alone", () => {
   it("keeps global filters when deselecting a cell", () => {
     const { result, fm } = setup(flatConfig, flatData, {}, globalFilter);
 
-    result.handleCellClickToFilter("0", "revenue", false, flatData[0]);
-    result.handleCellClickToFilter("0", "revenue", false, flatData[0]);
+    result.handleCellClickToFilter(rowId("US"), "revenue", false, flatData[0]);
+    result.handleCellClickToFilter(rowId("US"), "revenue", false, flatData[0]);
 
     expect(sel(result).cellSelections.size).toBe(0);
     expect(selectedValues(fm, "country")).toEqual([]);
@@ -725,11 +771,11 @@ describe("unrelated global filters are left alone", () => {
 
     const { result, fm } = setup(nestedConfig, nestedData, {}, globalFilter);
 
-    result.handleCellClickToFilter("1", "country", true, nestedData[0]);
+    result.handleCellClickToFilter(rowId("US"), "country", true, nestedData[0]);
     expect(sel(result).rowHeaderSelections.size).toBe(1);
     expect(selectedValues(fm, "country")).toEqual(["US"]);
 
-    result.handleCellClickToFilter("1", "country", true, nestedData[0]);
+    result.handleCellClickToFilter(rowId("US"), "country", true, nestedData[0]);
 
     expect(sel(result).rowHeaderSelections.size).toBe(0);
     expect(selectedValues(fm, "country")).toEqual([]);
@@ -797,14 +843,14 @@ describe("unrelated global filters are left alone", () => {
     const { result, fm } = setup(nestedConfig, nestedData, {}, globalFilter);
 
     result.handleCellClickToFilter(
-      "1.0",
+      rowId("Zoom", "US-East"),
       "revenue",
       false,
       nestedData[0].subRows![0],
     );
     expect(selectedValues(fm, "inner")).toEqual(["US-East"]);
 
-    result.handleCellClickToFilter("1", "outer", true, nestedData[0]);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, nestedData[0]);
 
     // The evicted child cell's inner value is dropped, the clicked row header's
     // outer value takes its place, and the global filter is untouched.
@@ -847,11 +893,16 @@ describe("header/cell mutual exclusivity", () => {
     const dkChild = dk({ outer: "Zoom", inner: "US-East" }, dims);
     const dkZoom = dk({ outer: "Zoom" }, dims);
 
-    result.handleCellClickToFilter("1.0", "revenue", false, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "revenue",
+      false,
+      childUSEast,
+    );
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(true);
     expect(selectedValues(fm, "inner")).toEqual(["US-East"]);
 
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
 
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(true);
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(false);
@@ -865,10 +916,15 @@ describe("header/cell mutual exclusivity", () => {
     const dkZoom = dk({ outer: "Zoom" }, dims);
     const dkChild = dk({ outer: "Zoom", inner: "US-East" }, dims);
 
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(true);
 
-    result.handleCellClickToFilter("1.0", "revenue", false, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "revenue",
+      false,
+      childUSEast,
+    );
 
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(true);
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(false);
@@ -879,8 +935,13 @@ describe("header/cell mutual exclusivity", () => {
   it("different lineage coexists: header + cell under different parent", () => {
     const { result } = setupNested();
 
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
-    result.handleCellClickToFilter("2.0", "revenue", false, childUSWest);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
+    result.handleCellClickToFilter(
+      rowId("Airtable", "US-West"),
+      "revenue",
+      false,
+      childUSWest,
+    );
 
     expect(sel(result).isRowHeaderSelected(dk({ outer: "Zoom" }, dims))).toBe(
       true,
@@ -901,12 +962,17 @@ describe("header/cell mutual exclusivity", () => {
     const dkChild = dk({ outer: "Zoom", inner: "US-East" }, dims);
 
     // Select child row header first
-    result.handleCellClickToFilter("1.0", "inner", true, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "inner",
+      true,
+      childUSEast,
+    );
     expect(sel(result).isRowHeaderSelected(dkChild)).toBe(true);
     expect(selectedValues(fm, "inner")).toEqual(["US-East"]);
 
     // Click parent row header — child must be evicted
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
 
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(true);
     expect(sel(result).isRowHeaderSelected(dkChild)).toBe(false);
@@ -923,11 +989,16 @@ describe("header/cell mutual exclusivity", () => {
     const dkChild = dk({ outer: "Zoom", inner: "US-East" }, dims);
 
     // Select parent first
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(true);
 
     // Click child row header — parent must be evicted
-    result.handleCellClickToFilter("1.0", "inner", true, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "inner",
+      true,
+      childUSEast,
+    );
 
     expect(sel(result).isRowHeaderSelected(dkChild)).toBe(true);
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(false);
@@ -942,11 +1013,16 @@ describe("header/cell mutual exclusivity", () => {
     const dkAirtableChild = dk({ outer: "Airtable", inner: "US-West" }, dims);
 
     // Select a child under a different parent first
-    result.handleCellClickToFilter("2.0", "inner", true, childUSWest);
+    result.handleCellClickToFilter(
+      rowId("Airtable", "US-West"),
+      "inner",
+      true,
+      childUSWest,
+    );
     expect(sel(result).isRowHeaderSelected(dkAirtableChild)).toBe(true);
 
     // Click Zoom parent — Airtable's child header is a different lineage, must coexist
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
 
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(true);
     expect(sel(result).isRowHeaderSelected(dkAirtableChild)).toBe(true);
@@ -961,12 +1037,17 @@ describe("header/cell mutual exclusivity", () => {
     const dkZoom = dk({ outer: "Zoom" }, dims);
 
     // Select a child row header first
-    result.handleCellClickToFilter("1.0", "inner", true, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "inner",
+      true,
+      childUSEast,
+    );
     expect(sel(result).isRowHeaderSelected(dkChildHeader)).toBe(true);
     expect(selectedValues(fm, "inner")).toEqual(["US-East"]);
 
     // Click parent row's measure cell — child row header must be evicted
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
 
     expect(sel(result).isCellSelected(dkZoom, "revenue")).toBe(true);
     expect(sel(result).isRowHeaderSelected(dkChildHeader)).toBe(false);
@@ -982,11 +1063,16 @@ describe("header/cell mutual exclusivity", () => {
     const dkChild = dk({ outer: "Zoom", inner: "US-East" }, dims);
 
     // Select parent row header first
-    result.handleCellClickToFilter("1", "outer", true, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "outer", true, parentZoom);
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(true);
 
     // Click child row's measure cell — parent row header must be evicted
-    result.handleCellClickToFilter("1.0", "revenue", false, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "revenue",
+      false,
+      childUSEast,
+    );
 
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(true);
     expect(sel(result).isRowHeaderSelected(dkZoom)).toBe(false);
@@ -1001,12 +1087,17 @@ describe("header/cell mutual exclusivity", () => {
     const dkZoom = dk({ outer: "Zoom" }, dims);
 
     // Select a child measure cell first
-    result.handleCellClickToFilter("1.0", "revenue", false, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "revenue",
+      false,
+      childUSEast,
+    );
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(true);
     expect(selectedValues(fm, "inner")).toEqual(["US-East"]);
 
     // Click the parent row's measure cell — child cell must be evicted
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
 
     expect(sel(result).isCellSelected(dkZoom, "revenue")).toBe(true);
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(false);
@@ -1029,9 +1120,14 @@ describe("header/cell mutual exclusivity", () => {
     };
     nestedData[0].subRows = [...dkChildExpanded, childUSWestUnderZoom];
 
-    result.handleCellClickToFilter("1.0", "revenue", false, childUSEast);
     result.handleCellClickToFilter(
-      "1.1",
+      rowId("Zoom", "US-East"),
+      "revenue",
+      false,
+      childUSEast,
+    );
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-West"),
       "revenue",
       false,
       childUSWestUnderZoom,
@@ -1039,7 +1135,7 @@ describe("header/cell mutual exclusivity", () => {
     expect(sel(result).cellSelections.size).toBe(2);
 
     // Click parent row cell — both children evicted
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
 
     expect(
       sel(result).isCellSelected(dk({ outer: "Zoom" }, dims), "revenue"),
@@ -1058,11 +1154,16 @@ describe("header/cell mutual exclusivity", () => {
     const dkChild = dk({ outer: "Zoom", inner: "US-East" }, dims);
 
     // Select parent row cell first
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
     expect(sel(result).isCellSelected(dkZoom, "revenue")).toBe(true);
 
     // Click child row cell — parent cell must be evicted
-    result.handleCellClickToFilter("1.0", "revenue", false, childUSEast);
+    result.handleCellClickToFilter(
+      rowId("Zoom", "US-East"),
+      "revenue",
+      false,
+      childUSEast,
+    );
 
     expect(sel(result).isCellSelected(dkChild, "revenue")).toBe(true);
     expect(sel(result).isCellSelected(dkZoom, "revenue")).toBe(false);
@@ -1076,12 +1177,17 @@ describe("header/cell mutual exclusivity", () => {
     const dkAirtableChild = dk({ outer: "Airtable", inner: "US-West" }, dims);
 
     // Select a cell under Airtable parent
-    result.handleCellClickToFilter("2.0", "revenue", false, childUSWest);
+    result.handleCellClickToFilter(
+      rowId("Airtable", "US-West"),
+      "revenue",
+      false,
+      childUSWest,
+    );
     expect(sel(result).isCellSelected(dkAirtableChild, "revenue")).toBe(true);
 
     // Click Zoom parent row cell — Airtable's child cell is a different
     // lineage and must coexist
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
 
     expect(
       sel(result).isCellSelected(dk({ outer: "Zoom" }, dims), "revenue"),
@@ -1098,8 +1204,13 @@ describe("header/cell mutual exclusivity", () => {
 
     // Two cells in the same parent row, different columns: same dimValues,
     // not in a strict subset/superset relationship — both must coexist.
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
-    result.handleCellClickToFilter("1", "other_measure", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
+    result.handleCellClickToFilter(
+      rowId("Zoom"),
+      "other_measure",
+      false,
+      parentZoom,
+    );
 
     expect(sel(result).isCellSelected(dkZoom, "revenue")).toBe(true);
     expect(sel(result).isCellSelected(dkZoom, "other_measure")).toBe(true);
@@ -1112,13 +1223,23 @@ describe("header/cell mutual exclusivity", () => {
     const { result, fm } = setupNested();
     const dkZoom = dk({ outer: "Zoom" }, dims);
 
-    result.handleCellClickToFilter("1", "revenue", false, parentZoom);
-    result.handleCellClickToFilter("1", "other_measure", false, parentZoom);
+    result.handleCellClickToFilter(rowId("Zoom"), "revenue", false, parentZoom);
+    result.handleCellClickToFilter(
+      rowId("Zoom"),
+      "other_measure",
+      false,
+      parentZoom,
+    );
     expect(selectedValues(fm, "outer")).toEqual(["Zoom"]);
 
     // Deselecting one of the two cells removes no dimension value, since the
     // remaining cell in the same row still needs outer=Zoom.
-    result.handleCellClickToFilter("1", "other_measure", false, parentZoom);
+    result.handleCellClickToFilter(
+      rowId("Zoom"),
+      "other_measure",
+      false,
+      parentZoom,
+    );
 
     expect(sel(result).isCellSelected(dkZoom, "revenue")).toBe(true);
     expect(sel(result).isCellSelected(dkZoom, "other_measure")).toBe(false);
@@ -1176,20 +1297,25 @@ describe("header/cell mutual exclusivity", () => {
       const dkZoom = dk({ outer: "Zoom" }, colDims);
 
       result.handleCellClickToFilter(
-        "1.0",
+        rowId("Zoom", "US-East"),
         childEastColId,
         false,
         childEastCol,
       );
       result.handleCellClickToFilter(
-        "1.1",
+        rowId("Zoom", "US-West"),
         childWestColId,
         false,
         childWestCol,
       );
       expect(sel(result).cellSelections.size).toBe(2);
 
-      result.handleCellClickToFilter("1", totalsColId, false, parentZoomCol);
+      result.handleCellClickToFilter(
+        rowId("Zoom"),
+        totalsColId,
+        false,
+        parentZoomCol,
+      );
 
       expect(sel(result).isCellSelected(dkZoom, totalsColId)).toBe(true);
       expect(sel(result).isCellSelected(dkChildEast, childEastColId)).toBe(
@@ -1211,13 +1337,13 @@ describe("header/cell mutual exclusivity", () => {
 
       // Children sit at different quarters
       result.handleCellClickToFilter(
-        "1.0",
+        rowId("Zoom", "US-East"),
         childEastColId,
         false,
         childEastCol,
       );
       result.handleCellClickToFilter(
-        "1.1",
+        rowId("Zoom", "US-West"),
         childWestColId,
         false,
         childWestCol,
@@ -1226,7 +1352,12 @@ describe("header/cell mutual exclusivity", () => {
 
       // Click parent's Q1-total cell — both children must be evicted even
       // though one is at Q2.
-      result.handleCellClickToFilter("1", q1TotalColId, false, parentZoomCol);
+      result.handleCellClickToFilter(
+        rowId("Zoom"),
+        q1TotalColId,
+        false,
+        parentZoomCol,
+      );
 
       expect(sel(result).isCellSelected(dkZoom, q1TotalColId)).toBe(true);
       expect(sel(result).isCellSelected(dkChildEast, childEastColId)).toBe(
@@ -1247,13 +1378,13 @@ describe("header/cell mutual exclusivity", () => {
       const dkZoom = dk({ outer: "Zoom" }, colDims);
 
       result.handleCellClickToFilter(
-        "1.0",
+        rowId("Zoom", "US-East"),
         childEastColId,
         false,
         childEastCol,
       );
       result.handleCellClickToFilter(
-        "1.1",
+        rowId("Zoom", "US-West"),
         childWestColId,
         false,
         childWestCol,
@@ -1262,7 +1393,12 @@ describe("header/cell mutual exclusivity", () => {
 
       // Click parent's Q1×Prod leaf cell — both children must be evicted
       // regardless of which column they sit in.
-      result.handleCellClickToFilter("1", q1ProdColId, false, parentZoomCol);
+      result.handleCellClickToFilter(
+        rowId("Zoom"),
+        q1ProdColId,
+        false,
+        parentZoomCol,
+      );
 
       expect(sel(result).isCellSelected(dkZoom, q1ProdColId)).toBe(true);
       expect(sel(result).isCellSelected(dkChildEast, childEastColId)).toBe(
@@ -1299,7 +1435,12 @@ describe("header/cell mutual exclusivity", () => {
     );
     const dkUS = dimKeyFromRow(nestedFlatData[0], ["country"]);
 
-    result.handleCellClickToFilter("1", naColId, false, nestedFlatData[0]);
+    result.handleCellClickToFilter(
+      rowId("US"),
+      naColId,
+      false,
+      nestedFlatData[0],
+    );
     expect(sel(result).isCellSelected(dkUS, naColId)).toBe(true);
     expect(selectedValues(fm, "country")).toEqual(["US"]);
 
@@ -1319,7 +1460,12 @@ describe("header/cell mutual exclusivity", () => {
     result.handleColumnHeaderClick({ region: "NA" });
     expect(sel(result).isColumnHeaderSelected({ region: "NA" })).toBe(true);
 
-    result.handleCellClickToFilter("1", naColId, false, nestedFlatData[0]);
+    result.handleCellClickToFilter(
+      rowId("US"),
+      naColId,
+      false,
+      nestedFlatData[0],
+    );
 
     expect(sel(result).isCellSelected(dkUS, naColId)).toBe(true);
     expect(sel(result).isColumnHeaderSelected({ region: "NA" })).toBe(false);
@@ -1333,7 +1479,12 @@ describe("header/cell mutual exclusivity", () => {
 
     result.handleColumnHeaderClick({ region: "NA" }); // header is NA
     // cell is in EU column, so they do NOT overlap
-    result.handleCellClickToFilter("1", euColId, false, nestedFlatData[0]);
+    result.handleCellClickToFilter(
+      rowId("US"),
+      euColId,
+      false,
+      nestedFlatData[0],
+    );
 
     expect(sel(result).isColumnHeaderSelected({ region: "NA" })).toBe(true);
     expect(sel(result).isCellSelected(dkUS, euColId)).toBe(true);
diff --git a/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.ts b/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.ts
index 7a669aac397..2f17b22f029 100644
--- a/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.ts
+++ b/web-common/src/features/canvas/components/pivot/pivot-click-to-filter.ts
@@ -20,6 +20,7 @@ import {
   dimKeyFromDimValues,
   dimKeyFromRow,
 } from "@rilldata/web-common/features/dashboards/pivot/pivot-click-selection";
+import { parentExpandKey } from "@rilldata/web-common/features/dashboards/pivot/pivot-expand-keys";
 import {
   type ExtractedFilter,
   type PivotRowSelectionState,
@@ -614,7 +615,7 @@ export function createPivotClickToFilter(
     const $clickSelection = get(clickSelectionStore);
 
     // In nested mode, row data stores all values under rowDimensions[0],
-    // so we must use positional rowId navigation to get correct dim→value pairs.
+    // so we must resolve the value-based rowId to get correct dim→value pairs.
     const isNested = !$config.isFlat;
     const dimValues = isNested
       ? Object.fromEntries(
@@ -627,7 +628,7 @@ export function createPivotClickToFilter(
     // For nested child rows (depth > 0), build dimKey from the fully-resolved
     // dimValues (which include parent dimension values); dimKeyFromRow only
     // sees rowDimensions[0] and would produce identical keys across parents.
-    const isNestedChild = isNested && rowId.includes(".");
+    const isNestedChild = isNested && parentExpandKey(rowId) !== "";
     const dk = isNestedChild
       ? dimKeyFromDimValues(dimValues, $config.rowDimensionNames)
       : dimKeyFromRow(rowData, $config.rowDimensionNames);
diff --git a/web-common/src/features/dashboards/pivot/FlatTable.svelte b/web-common/src/features/dashboards/pivot/FlatTable.svelte
index e4386dcdc5c..cd67966c12f 100644
--- a/web-common/src/features/dashboards/pivot/FlatTable.svelte
+++ b/web-common/src/features/dashboards/pivot/FlatTable.svelte
@@ -28,6 +28,7 @@
     type PivotClickSelectionState,
     dimKeyFromRow,
   } from "./pivot-click-selection";
+  import { PIVOT_TOTALS_ROW_ID } from "./pivot-expand-keys";
   import type { PivotRowSelectionState } from "./pivot-row-selection";
   import type { CellFormatter } from "./pivot-conditional-formatting";
   import PivotHeaderLabel from "./PivotHeaderLabel.svelte";
@@ -76,9 +77,10 @@
 
   $: headers = headerGroups[0].headers;
 
-  // The totals row is always tanstack row "0" (see PivotTable.svelte). When
-  // pinned to the bottom it is skipped in the virtualized body and rendered
-  // once more in a sticky <tfoot>, so no row ids or index math change.
+  // The totals row is always the first tanstack row, with id
+  // PIVOT_TOTALS_ROW_ID (see PivotTable.svelte). When pinned to the bottom it
+  // is skipped in the virtualized body and rendered once more in a sticky
+  // <tfoot>, so no row ids or index math change.
   $: totalsRowAtBottom = !!totalsRow && totalsRowPosition === "bottom";
 
   // Initialize column lengths if not already set
@@ -291,7 +293,7 @@
   {@const rowId = rows[rowIndex].id}
   {@const rowData = rows[rowIndex].original}
   {@const dk = dimKeyFromRow(rowData, config?.rowDimensionNames ?? [])}
-  {@const isTotalsRow = !!totalsRow && rowId === "0"}
+  {@const isTotalsRow = !!totalsRow && rowId === PIVOT_TOTALS_ROW_ID}
   {@const isSelected = rowSelectionState?.isRowSelected(rowData) ?? false}
   {@const hasClickedCell = clickSelection?.hasSelectedCellInRow(dk) ?? false}
   {@const effectiveDimIdx = computeEffectiveDimIdx(
diff --git a/web-common/src/features/dashboards/pivot/NestedTable.svelte b/web-common/src/features/dashboards/pivot/NestedTable.svelte
index 8cfad08bfa4..84908cc046a 100644
--- a/web-common/src/features/dashboards/pivot/NestedTable.svelte
+++ b/web-common/src/features/dashboards/pivot/NestedTable.svelte
@@ -29,6 +29,7 @@
     getNestedRowDimensionWidthKey,
     COLUMN_WIDTH_CONSTANTS as WIDTHS,
   } from "./pivot-column-width-utils";
+  import { PIVOT_TOTALS_ROW_ID } from "./pivot-expand-keys";
   import type { PivotRowSelectionState } from "./pivot-row-selection";
   import {
     computeAncestorRowIds,
@@ -120,9 +121,10 @@
   $: hasExpandableRows = rowDimensions.length > 1;
   $: hasMeasures = measures.length > 0;
 
-  // The totals row is always tanstack row "0" (see PivotTable.svelte). When
-  // pinned to the bottom it is skipped in the virtualized body and rendered
-  // once more in a sticky <tfoot>, so no row ids or index math change.
+  // The totals row is always the first tanstack row, with id
+  // PIVOT_TOTALS_ROW_ID (see PivotTable.svelte). When pinned to the bottom it
+  // is skipped in the virtualized body and rendered once more in a sticky
+  // <tfoot>, so no row ids or index math change.
   $: totalsRowAtBottom = !!totalsRow && totalsRowPosition === "bottom";
   $: rowDimensionNames = rowDimensions.map((d) => d.name);
   $: rowDimensionLabel = getRowNestedLabel(rowDimensions);
@@ -631,7 +633,7 @@
     rows[rowIndex].depth > 0
       ? nestedDimKeyFromRow(rows[rowIndex], rowDimensionNames)
       : dimKeyFromRow(rowData, rowDimensionNames)}
-  {@const isTotalsRow = !!totalsRow && rowId === "0"}
+  {@const isTotalsRow = !!totalsRow && rowId === PIVOT_TOTALS_ROW_ID}
   {@const filterSelected =
     rowSelectionState?.isRowSelected(
       rowData,
diff --git a/web-common/src/features/dashboards/pivot/PivotTable.svelte b/web-common/src/features/dashboards/pivot/PivotTable.svelte
index 6fdb8d471f2..6b62acdfcfa 100644
--- a/web-common/src/features/dashboards/pivot/PivotTable.svelte
+++ b/web-common/src/features/dashboards/pivot/PivotTable.svelte
@@ -18,6 +18,13 @@
     isShowMoreRow,
     splitPivotChips,
   } from "@rilldata/web-common/features/dashboards/pivot/pivot-utils";
+  import {
+    buildExpandKey,
+    childExpandKey,
+    encodeExpandKeyValue,
+    parentExpandKey,
+    PIVOT_TOTALS_ROW_ID,
+  } from "@rilldata/web-common/features/dashboards/pivot/pivot-expand-keys";
   import { copyToClipboard } from "@rilldata/web-common/lib/actions/copy-to-clipboard";
   import {
     createVirtualizer,
@@ -89,15 +96,30 @@
   export let clickSelection: PivotClickSelectionState | undefined = undefined;
 
   const options: Readable<TableOptions<PivotDataRow>> = derived(
-    [pivotDataStore, pivotState],
-    ([pivotData, state]) => {
+    [pivotDataStore, pivotState, config],
+    ([pivotData, state, cfg]) => {
       let tableData = [...pivotData.data];
       if (pivotData.totalsRowData) {
         tableData = [pivotData.totalsRowData, ...pivotData.data];
       }
+      const totalsRowData = pivotData.totalsRowData;
+      const rowDims = cfg.rowDimensionNames;
       return {
         data: tableData,
         columns: pivotData.columnDef,
+        // Value-based, hierarchical row ids (parent id + this row's value) so
+        // expansion survives sorting, adding a field, and data refreshes.
+        getRowId: (row, _index, parent) => {
+          if (totalsRowData && row === totalsRowData)
+            return PIVOT_TOTALS_ROW_ID;
+          if (cfg.isFlat) {
+            return buildExpandKey(rowDims.map((dim) => row[dim]));
+          }
+          const anchor = rowDims[0];
+          return parent
+            ? childExpandKey(parent.id, row[anchor])
+            : encodeExpandKeyValue(row[anchor]);
+        },
         state: {
           expanded: state.expanded,
           sorting: state.sorting,
@@ -240,7 +262,7 @@
     if (needsDomains) {
       for (const row of flatRows) {
         // Always skip the prepended grand-totals row.
-        if (hasTotalsRow && row.id === "0") continue;
+        if (hasTotalsRow && row.id === PIVOT_TOTALS_ROW_ID) continue;
         const target = row.subRows.length > 0 ? parentValues : leafValues;
         for (const cell of row.getAllCells()) {
           const meta = cell.column.columnDef.meta;
@@ -364,21 +386,20 @@
 
       if (!nextLimit) return;
 
-      // Check if this is the outermost dimension or a nested dimension
-      // Outermost dimension has rowId like "0", "1", etc. (no dots)
-      // Nested dimensions have rowId like "0.1", "0.1.2", etc.
-      const isOutermostDimension = !rowId.includes(".");
+      // The outermost "Show more" row sits at the top level (its parent key
+      // is the root ""); a nested one has a real parent node whose child
+      // limit we raise.
+      const parentKey = parentExpandKey(rowId);
 
-      if (isOutermostDimension) {
+      if (parentKey === "") {
         // Handle outermost dimension "Show more" click
         if (setPivotOutermostRowLimit) {
           setPivotOutermostRowLimit(nextLimit);
         }
       } else {
         // Handle nested dimension "Show more" click
-        const expandIndex = rowId.split(".").slice(0, -1).join(".");
-        if (expandIndex && setPivotRowLimitForExpanded) {
-          setPivotRowLimitForExpanded(expandIndex, nextLimit);
+        if (setPivotRowLimitForExpanded) {
+          setPivotRowLimitForExpanded(parentKey, nextLimit);
         }
       }
       return;
@@ -391,7 +412,7 @@
       if (row.getCanExpand()) row.getToggleExpandedHandler()();
     } else {
       // Skip totals row for filtering
-      const isTotalsRow = totalsRow && rowId === "0";
+      const isTotalsRow = totalsRow && rowId === PIVOT_TOTALS_ROW_ID;
       if (isTotalsRow && onCellClickToFilter) {
         return;
       }
diff --git a/web-common/src/features/dashboards/pivot/pivot-expand-keys.spec.ts b/web-common/src/features/dashboards/pivot/pivot-expand-keys.spec.ts
new file mode 100644
index 00000000000..1c07709d1e6
--- /dev/null
+++ b/web-common/src/features/dashboards/pivot/pivot-expand-keys.spec.ts
@@ -0,0 +1,53 @@
+import { describe, expect, it } from "vitest";
+import {
+  buildExpandKey,
+  childExpandKey,
+  expandKeyDepth,
+  expandKeySegments,
+  parentExpandKey,
+} from "./pivot-expand-keys";
+
+describe("pivot-expand-keys", () => {
+  it("round-trips a value path through build/segments", () => {
+    const values = ["Galatea-Stories", "facebook", "Jul 2026"];
+    const key = buildExpandKey(values);
+    expect(expandKeySegments(key)).toEqual(values);
+    expect(expandKeyDepth(key)).toBe(3);
+  });
+
+  it("keeps values that contain dots or spaces intact", () => {
+    const values = ["a.b.c", "x y z"];
+    const key = buildExpandKey(values);
+    expect(expandKeySegments(key)).toEqual(values);
+    expect(expandKeyDepth(key)).toBe(2);
+  });
+
+  it("encodes null distinctly from a genuinely absent level", () => {
+    const withNull = buildExpandKey(["app", null]);
+    const shallow = buildExpandKey(["app"]);
+    expect(withNull).not.toBe(shallow);
+    expect(expandKeyDepth(withNull)).toBe(2);
+    expect(expandKeyDepth(shallow)).toBe(1);
+  });
+
+  it("computes the parent by stripping the deepest segment", () => {
+    const key = buildExpandKey(["app", "src", "month"]);
+    const parent = parentExpandKey(key);
+    expect(expandKeySegments(parent)).toEqual(["app", "src"]);
+    expect(parentExpandKey(buildExpandKey(["app"]))).toBe("");
+    expect(parentExpandKey("")).toBe("");
+  });
+
+  it("childExpandKey extends a parent and is inverse of parentExpandKey", () => {
+    const parent = buildExpandKey(["app", "src"]);
+    const child = childExpandKey(parent, "month");
+    expect(expandKeySegments(child)).toEqual(["app", "src", "month"]);
+    expect(parentExpandKey(child)).toBe(parent);
+    expect(childExpandKey("", "app")).toBe(buildExpandKey(["app"]));
+  });
+
+  it("treats the empty root key as depth 0", () => {
+    expect(expandKeyDepth("")).toBe(0);
+    expect(expandKeySegments("")).toEqual([]);
+  });
+});
diff --git a/web-common/src/features/dashboards/pivot/pivot-expand-keys.ts b/web-common/src/features/dashboards/pivot/pivot-expand-keys.ts
new file mode 100644
index 00000000000..8809267a65b
--- /dev/null
+++ b/web-common/src/features/dashboards/pivot/pivot-expand-keys.ts
@@ -0,0 +1,44 @@
+/**
+ * Value-based keys for pivot row expansion. A row is keyed by the dimension
+ * values from the root to it, NUL-joined and hierarchical, so the key stays
+ * stable across sorting, adding a field, and data refreshes. Uses the same
+ * separator and null sentinel as the dimKeys in pivot-click-selection.ts,
+ * except that undefined also maps to the sentinel here.
+ */
+
+// NUL separator, since dimension values won't contain it.
+export const EXPAND_KEY_SEP = "\0";
+
+// Sentinel for null values, so a null at depth N differs from an absent level.
+// A literal "<NULL>" string value encodes the same way, which only matters if
+// both appear under the same parent; the dimKeys make the same trade-off.
+const NULL_SENTINEL = "<NULL>";
+
+// The leading separator can't occur in a real id, so this can't collide.
+export const PIVOT_TOTALS_ROW_ID = EXPAND_KEY_SEP + "totals";
+
+export function encodeExpandKeyValue(value: unknown): string {
+  return value === null || value === undefined ? NULL_SENTINEL : String(value);
+}
+
+export function buildExpandKey(values: unknown[]): string {
+  return values.map(encodeExpandKeyValue).join(EXPAND_KEY_SEP);
+}
+
+export function expandKeySegments(key: string): string[] {
+  return key === "" ? [] : key.split(EXPAND_KEY_SEP);
+}
+
+export function expandKeyDepth(key: string): number {
+  return expandKeySegments(key).length;
+}
+
+export function parentExpandKey(key: string): string {
+  const i = key.lastIndexOf(EXPAND_KEY_SEP);
+  return i === -1 ? "" : key.slice(0, i);
+}
+
+export function childExpandKey(parentKey: string, value: unknown): string {
+  const segment = encodeExpandKeyValue(value);
+  return parentKey === "" ? segment : parentKey + EXPAND_KEY_SEP + segment;
+}
diff --git a/web-common/src/features/dashboards/pivot/pivot-expansion.spec.ts b/web-common/src/features/dashboards/pivot/pivot-expansion.spec.ts
index 74eee7c7385..e938a859c24 100644
--- a/web-common/src/features/dashboards/pivot/pivot-expansion.spec.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-expansion.spec.ts
@@ -1,13 +1,32 @@
-import { describe, expect, it } from "vitest";
+import { readable } from "svelte/store";
+import { beforeEach, describe, expect, it, vi } from "vitest";
 import { LOADING_CELL } from "@rilldata/web-common/features/dashboards/pivot/pivot-constants";
 import { createAndExpression } from "@rilldata/web-common/features/dashboards/stores/filter-utils";
-import { addExpandedDataToPivot } from "./pivot-expansion";
-import { type PivotDataRow, type PivotDataStoreConfig } from "./types";
+import { buildExpandKey } from "./pivot-expand-keys";
+import {
+  addExpandedDataToPivot,
+  getValuesForExpandedKey,
+  queryExpandedRowMeasureValues,
+} from "./pivot-expansion";
+import { getAxisForDimensions } from "./pivot-queries";
+import {
+  type PivotDashboardContext,
+  type PivotDataRow,
+  type PivotDataStoreConfig,
+} from "./types";
 
-function getConfig(showTotalsRow: boolean): PivotDataStoreConfig {
+vi.mock("./pivot-queries", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./pivot-queries")>()),
+  getAxisForDimensions: vi.fn(() => readable({ isFetching: true })),
+}));
+
+function getConfig(
+  showTotalsRow: boolean,
+  rowDimensionNames = ["publisher", "campaign"],
+): PivotDataStoreConfig {
   return {
     measureNames: ["impressions"],
-    rowDimensionNames: ["publisher", "campaign"],
+    rowDimensionNames,
     colDimensionNames: [],
     allMeasures: [],
     allDimensions: [],
@@ -38,76 +57,168 @@ function getConfig(showTotalsRow: boolean): PivotDataStoreConfig {
   } as unknown as PivotDataStoreConfig;
 }
 
-describe("pivot expansion", () => {
-  it("adds expanded rows at the correct index when totals row is hidden", () => {
+describe("pivot expansion (value-based keys)", () => {
+  it("fills the node matched by dimension value, regardless of totals row", () => {
+    for (const showTotals of [false, true]) {
+      const tableData: PivotDataRow[] = [
+        { publisher: "A", subRows: [{ publisher: LOADING_CELL }] },
+        { publisher: "B", subRows: [{ publisher: LOADING_CELL }] },
+      ];
+
+      addExpandedDataToPivot(
+        getConfig(showTotals),
+        tableData,
+        ["publisher", "campaign"],
+        {},
+        [
+          {
+            isFetching: false,
+            expandIndex: buildExpandKey(["B"]),
+            rowDimensionValues: ["B"],
+            totals: [{ campaign: "campaign-1", impressions: 10 }],
+            data: [],
+          },
+        ],
+      );
+
+      // Row "A" is untouched; row "B" (matched by value, not position) is filled.
+      expect(tableData[0].subRows?.[0]?.publisher).toBe(LOADING_CELL);
+      expect(tableData[1].subRows?.[0]).toMatchObject({
+        publisher: "campaign-1",
+        campaign: "campaign-1",
+        impressions: 10,
+      });
+    }
+  });
+
+  it("resolves a nested value path to the correct deep node", () => {
     const tableData: PivotDataRow[] = [
       {
         publisher: "A",
-        subRows: [{ publisher: LOADING_CELL }],
-      },
-      {
-        publisher: "B",
-        subRows: [{ publisher: LOADING_CELL }],
+        subRows: [
+          { publisher: "camp1", subRows: [{ publisher: LOADING_CELL }] },
+        ],
       },
     ];
 
     addExpandedDataToPivot(
-      getConfig(false),
+      getConfig(true, ["publisher", "campaign", "adgroup"]),
       tableData,
-      ["publisher", "campaign"],
+      ["publisher", "campaign", "adgroup"],
       {},
       [
         {
           isFetching: false,
-          expandIndex: "1",
-          rowDimensionValues: ["B"],
-          totals: [{ campaign: "campaign-1", impressions: 10 }],
+          expandIndex: buildExpandKey(["A", "camp1"]),
+          rowDimensionValues: ["A", "camp1"],
+          totals: [{ adgroup: "ad-1", impressions: 5 }],
           data: [],
         },
       ],
     );
 
-    expect(tableData[0].subRows?.[0]?.publisher).toBe(LOADING_CELL);
-    expect(tableData[1].subRows?.[0]).toMatchObject({
-      publisher: "campaign-1",
-      campaign: "campaign-1",
-      impressions: 10,
+    expect(tableData[0].subRows?.[0]?.subRows?.[0]).toMatchObject({
+      publisher: "ad-1",
+      adgroup: "ad-1",
+      impressions: 5,
     });
   });
 
-  it("keeps the totals row offset when totals row is visible", () => {
+  it("does nothing when the value path matches no row", () => {
     const tableData: PivotDataRow[] = [
-      {
-        publisher: "A",
-        subRows: [{ publisher: LOADING_CELL }],
-      },
-      {
-        publisher: "B",
-        subRows: [{ publisher: LOADING_CELL }],
-      },
+      { publisher: "A", subRows: [{ publisher: LOADING_CELL }] },
     ];
-
     addExpandedDataToPivot(
-      getConfig(true),
+      getConfig(false),
       tableData,
       ["publisher", "campaign"],
       {},
       [
         {
           isFetching: false,
-          expandIndex: "2",
-          rowDimensionValues: ["B"],
-          totals: [{ campaign: "campaign-1", impressions: 10 }],
+          expandIndex: buildExpandKey(["does-not-exist"]),
+          rowDimensionValues: ["does-not-exist"],
+          totals: [{ campaign: "c", impressions: 1 }],
           data: [],
         },
       ],
     );
-
     expect(tableData[0].subRows?.[0]?.publisher).toBe(LOADING_CELL);
-    expect(tableData[1].subRows?.[0]).toMatchObject({
-      publisher: "campaign-1",
-      campaign: "campaign-1",
-      impressions: 10,
-    });
+  });
+});
+
+describe("getValuesForExpandedKey", () => {
+  const tableData: PivotDataRow[] = [
+    {
+      publisher: "A",
+      subRows: [{ publisher: "camp1" }, { publisher: "camp2" }],
+    },
+    { publisher: "B", subRows: [{ publisher: "camp3" }] },
+  ];
+
+  it("returns the actual values along the matched path", () => {
+    expect(
+      getValuesForExpandedKey(
+        tableData,
+        ["publisher", "campaign"],
+        buildExpandKey(["B"]),
+      ),
+    ).toEqual(["B"]);
+    expect(
+      getValuesForExpandedKey(
+        tableData,
+        ["publisher", "campaign"],
+        buildExpandKey(["A", "camp2"]),
+      ),
+    ).toEqual(["A", "camp2"]);
+  });
+
+  it("stops at the deepest resolvable segment", () => {
+    expect(
+      getValuesForExpandedKey(
+        tableData,
+        ["publisher", "campaign"],
+        buildExpandKey(["A", "missing"]),
+      ),
+    ).toEqual(["A"]);
+  });
+});
+
+describe("queryExpandedRowMeasureValues", () => {
+  const rowDimensionNames = ["publisher", "domain", "campaign"];
+  // Rows are [publisher, domain, campaign], so A's children are domains.
+  const tableData: PivotDataRow[] = [
+    { publisher: "A", subRows: [{ publisher: "example.com" }] },
+  ];
+
+  function query(expandedKey: string) {
+    const config = getConfig(false, rowDimensionNames);
+    config.pivot.expanded = { [expandedKey]: true };
+    return queryExpandedRowMeasureValues(
+      {} as PivotDashboardContext,
+      config,
+      tableData,
+      {},
+      {},
+    );
+  }
+
+  beforeEach(() => {
+    vi.mocked(getAxisForDimensions).mockClear();
+  });
+
+  it("queries the next dimension for a fully resolved key", () => {
+    query(buildExpandKey(["A"]));
+    expect(getAxisForDimensions).toHaveBeenCalledTimes(1);
+    expect(vi.mocked(getAxisForDimensions).mock.calls[0][2]).toEqual([
+      "domain",
+    ]);
+  });
+
+  it("does not query for a key that only partially resolves", () => {
+    // Expanded as [publisher, campaign] before domain was inserted: "camp1"
+    // no longer matches a row at depth 1, so only "A" resolves.
+    query(buildExpandKey(["A", "camp1"]));
+    expect(getAxisForDimensions).not.toHaveBeenCalled();
   });
 });
diff --git a/web-common/src/features/dashboards/pivot/pivot-expansion.ts b/web-common/src/features/dashboards/pivot/pivot-expansion.ts
index d1382fe31da..66352771251 100644
--- a/web-common/src/features/dashboards/pivot/pivot-expansion.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-expansion.ts
@@ -3,6 +3,11 @@ import {
   MAX_ROW_EXPANSION_LIMIT,
   SHOW_MORE_BUTTON,
 } from "@rilldata/web-common/features/dashboards/pivot/pivot-constants";
+import {
+  encodeExpandKeyValue,
+  expandKeyDepth,
+  expandKeySegments,
+} from "@rilldata/web-common/features/dashboards/pivot/pivot-expand-keys";
 import { mergeFilters } from "@rilldata/web-common/features/dashboards/pivot/pivot-merge-filters";
 import {
   createAndExpression,
@@ -59,26 +64,21 @@ export function getValuesForExpandedKey(
   tableData: PivotDataRow[],
   rowDimensions: string[],
   key: string,
-  hasTotalsRow = true,
 ): string[] {
-  const indices = key.split(".").map((index) => parseInt(index, 10));
-
-  if (hasTotalsRow) {
-    // The first row is always the totals row for the expanded context with measures
-    indices[0] = indices[0] - 1;
-  }
-
-  // Retrieve the value from the nested array
-  let currentValue: PivotDataRow[] | undefined = tableData;
+  // Each row stores its own value under rowDimensions[0] at every depth, so
+  // match key segments against that to resolve a key to the actual values.
+  const anchor = rowDimensions[0];
   const dimensionValues: string[] = [];
+  let currentRows: PivotDataRow[] | undefined = tableData;
 
-  indices.forEach((index, i) => {
-    if (!currentValue?.[index]) {
-      return;
-    }
-    dimensionValues.push(currentValue[index]?.[rowDimensions[i]] as string);
-    currentValue = currentValue[index]?.subRows;
-  });
+  for (const segment of expandKeySegments(key)) {
+    const node = currentRows?.find(
+      (row) => encodeExpandKeyValue(row[anchor]) === segment,
+    );
+    if (!node) break;
+    dimensionValues.push(node[anchor] as string);
+    currentRows = node.subRows;
+  }
   return dimensionValues;
 }
 
@@ -201,7 +201,7 @@ export function queryExpandedRowMeasureValues(
   }
   return derived(
     Object.keys(expanded)?.map((expandIndex) => {
-      const nestLevel = expandIndex?.split(".")?.length;
+      const nestLevel = expandKeyDepth(expandIndex);
 
       if (nestLevel >= rowDimensionNames.length)
         return readable({
@@ -216,12 +216,14 @@ export function queryExpandedRowMeasureValues(
         tableData,
         rowDimensionNames,
         expandIndex,
-        config.pivot?.showTotalsRow !== false && numMeasures > 0,
       );
 
+      // A key that resolves only partway is either still loading or stale
+      // (e.g. a dimension was inserted above it), so don't query with a
+      // partial filter.
       if (
         !anchorDimension ||
-        !values.length ||
+        values.length !== nestLevel ||
         values.some((v) => v === undefined || v === LOADING_CELL)
       )
         return readable({
@@ -478,35 +480,21 @@ export function addExpandedDataToPivot(
     const rowValues = expandedRowData.rowDimensionValues;
 
     if (rowValues.length === 0) return;
-    const indices = expandedRowData.expandIndex
-      .split(".")
-      .map((index) => parseInt(index, 10));
-
-    if (
-      config.pivot?.showTotalsRow !== false &&
-      config.measureNames.length > 0
-    ) {
-      // The first row is always the totals row for the expanded context with measures
-      indices[0] = indices[0] - 1;
-    }
+    const segments = expandKeySegments(expandedRowData.expandIndex);
 
-    let parent: PivotDataRow[] = pivotData; // Keep a reference to the parent array
-    let lastIdx = 0;
-
-    // Traverse the data array to the right position
-    for (let i = 0; i < indices.length; i++) {
-      if (!parent[indices[i]]) break;
-      if (i < indices.length - 1) {
-        const subRows = parent[indices[i]].subRows;
-        if (!subRows) break;
-        parent = subRows;
-      }
-      lastIdx = indices[i];
+    let node: PivotDataRow | undefined;
+    let currentRows: PivotDataRow[] | undefined = pivotData;
+    for (const segment of segments) {
+      node = currentRows?.find(
+        (row) => encodeExpandKeyValue(row[rowDimensions[0]]) === segment,
+      );
+      if (!node) break;
+      currentRows = node.subRows;
     }
 
-    // Update the specific array at the position
-    if (parent[lastIdx] && parent[lastIdx].subRows) {
-      const anchorDimension = rowDimensions[indices.length];
+    // Update the node's subRows in place
+    if (node && node.subRows) {
+      const anchorDimension = rowDimensions[segments.length];
 
       let skeletonSubTable: PivotDataRow[] = [
         { [anchorDimension]: LOADING_CELL },
@@ -540,7 +528,7 @@ export function addExpandedDataToPivot(
            * is greater than number of nest levels expanded except
            * for the last level
            */
-          if (numRowDimensions - 1 > indices.length) {
+          if (numRowDimensions - 1 > segments.length) {
             newRow.subRows = [{ [rowDimensions[0]]: LOADING_CELL }];
           }
           return newRow;
@@ -558,7 +546,7 @@ export function addExpandedDataToPivot(
         } as PivotDataRow);
       }
 
-      parent[lastIdx].subRows = mappedSubRows;
+      node.subRows = mappedSubRows;
     }
   });
   return pivotData;
diff --git a/web-common/src/features/dashboards/pivot/pivot-filter-scope.spec.ts b/web-common/src/features/dashboards/pivot/pivot-filter-scope.spec.ts
index 60265ebf0fc..6cdf991fe55 100644
--- a/web-common/src/features/dashboards/pivot/pivot-filter-scope.spec.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-filter-scope.spec.ts
@@ -17,6 +17,7 @@ import {
 import type { V1Expression } from "@rilldata/web-common/runtime-client";
 import { describe, expect, it } from "vitest";
 import { buildFinalPivotStateDetails } from "./pivot-data-assembly";
+import { buildExpandKey } from "./pivot-expand-keys";
 import {
   getFiltersForColumnHeader,
   getFiltersForRowData,
@@ -76,7 +77,11 @@ describe("pivot filter builders exclude the global where filter", () => {
   });
 
   it("getFiltersForRowHeader", () => {
-    const result = getFiltersForRowHeader(makeConfig(), "0", FLAT_DATA);
+    const result = getFiltersForRowHeader(
+      makeConfig(),
+      buildExpandKey(["US"]),
+      FLAT_DATA,
+    );
 
     expect(identsIn(result.filters)).toEqual(["country"]);
   });
@@ -92,7 +97,7 @@ describe("pivot filter builders exclude the global where filter", () => {
   it("getFiltersForCell on a flat table", () => {
     const result = getFiltersForCell(
       makeConfig(),
-      "0",
+      buildExpandKey(["US"]),
       "revenue",
       {},
       FLAT_DATA,
@@ -110,7 +115,7 @@ describe("pivot filter builders exclude the global where filter", () => {
 
     const result = getFiltersForCell(
       config,
-      "0",
+      buildExpandKey(["US"]),
       "c0v0m0",
       { region: ["NA", "EU"] },
       FLAT_DATA,
@@ -143,7 +148,7 @@ describe("rows viewer cell filters include the global where filter", () => {
   it("merges config.whereFilter into activeCellFilters", () => {
     const config = makeConfig({
       pivot: {
-        activeCell: { rowId: "0", columnId: "revenue" },
+        activeCell: { rowId: buildExpandKey(["US"]), columnId: "revenue" },
         rowPage: 1,
         showTotalsRow: false,
         sorting: [],
diff --git a/web-common/src/features/dashboards/pivot/pivot-row-selection.ts b/web-common/src/features/dashboards/pivot/pivot-row-selection.ts
index 3717d98d1db..93a6cbbc36a 100644
--- a/web-common/src/features/dashboards/pivot/pivot-row-selection.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-row-selection.ts
@@ -39,17 +39,10 @@ function getRawRowValues(
   rowId: string,
   tableData: PivotDataRow[],
 ): string[] {
-  const { rowDimensionNames, measureNames, isFlat } = config;
-  const hasTotalsRow =
-    config.pivot?.showTotalsRow !== false && measureNames.length > 0;
+  const { rowDimensionNames, isFlat } = config;
   return isFlat
-    ? getValuesForFlatTable(tableData, rowDimensionNames, rowId, hasTotalsRow)
-    : getValuesForExpandedKey(
-        tableData,
-        rowDimensionNames,
-        rowId,
-        hasTotalsRow,
-      );
+    ? getValuesForFlatTable(tableData, rowDimensionNames, rowId)
+    : getValuesForExpandedKey(tableData, rowDimensionNames, rowId);
 }
 
 /**
@@ -77,7 +70,7 @@ export function getDimensionValuesForRow(
 
 /**
  * Like getDimensionValuesForRow but reads values directly from a PivotDataRow
- * instead of using positional rowId indexing. Stable across sorting.
+ * instead of resolving a rowId against the table data.
  */
 export function getDimensionValuesFromRowData(
   config: PivotDataStoreConfig,
diff --git a/web-common/src/features/dashboards/pivot/pivot-selection-indices.spec.ts b/web-common/src/features/dashboards/pivot/pivot-selection-indices.spec.ts
index 1f85c9733bc..411afd5b118 100644
--- a/web-common/src/features/dashboards/pivot/pivot-selection-indices.spec.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-selection-indices.spec.ts
@@ -5,6 +5,7 @@ import {
   columnHeaderKey,
   nestedDimKeyFromRow,
 } from "./pivot-click-selection";
+import { buildExpandKey } from "./pivot-expand-keys";
 import {
   computeAncestorRowIds,
   computeCellSelectedColDimGroupIndices,
@@ -296,10 +297,20 @@ describe("computeAncestorRowIds", () => {
   const rowDimensionNames = ["A", "B", "C"];
 
   // Tree: A expanded, B expanded. Visible rows: aRow, bRow, c1Row, c2Row.
-  const aRow = makeRow("1", 0, "a_val", []);
-  const bRow = makeRow("1.0", 1, "b_val", [aRow]);
-  const c1Row = makeRow("1.0.0", 2, "c1_val", [aRow, bRow]);
-  const c2Row = makeRow("1.0.1", 2, "c2_val", [aRow, bRow]);
+  const aRow = makeRow(buildExpandKey(["a_val"]), 0, "a_val", []);
+  const bRow = makeRow(buildExpandKey(["a_val", "b_val"]), 1, "b_val", [aRow]);
+  const c1Row = makeRow(
+    buildExpandKey(["a_val", "b_val", "c1_val"]),
+    2,
+    "c1_val",
+    [aRow, bRow],
+  );
+  const c2Row = makeRow(
+    buildExpandKey(["a_val", "b_val", "c2_val"]),
+    2,
+    "c2_val",
+    [aRow, bRow],
+  );
   const allRows = [aRow, bRow, c1Row, c2Row];
 
   it("B header clicked with C rows visible: B's own id is NOT in ancestor set", () => {
@@ -322,9 +333,9 @@ describe("computeAncestorRowIds", () => {
     const ids = computeAncestorRowIds(selection, allRows, rowDimensionNames);
 
     // A's rowId "1" should be in the set (A is an ancestor of B).
-    expect(ids.has("1")).toBe(true);
+    expect(ids.has(buildExpandKey(["a_val"]))).toBe(true);
     // B's own rowId "1.0" must NOT be in the set — B is the clicked row.
-    expect(ids.has("1.0")).toBe(false);
+    expect(ids.has(buildExpandKey(["a_val", "b_val"]))).toBe(false);
   });
 
   it("B header clicked and a C row has a null leaf value: keys do not collide", () => {
@@ -332,7 +343,12 @@ describe("computeAncestorRowIds", () => {
     // landmark is null for a given city+agency pair). The dimKey for
     // such a child row must remain distinct from its B parent's dk so
     // B's own selection does not bleed into a null-valued descendant.
-    const c1RowNullLeaf = makeRow("1.0.0", 2, null, [aRow, bRow]);
+    const c1RowNullLeaf = makeRow(
+      buildExpandKey(["a_val", "b_val", "c1_null"]),
+      2,
+      null,
+      [aRow, bRow],
+    );
     const rows = [aRow, bRow, c1RowNullLeaf, c2Row];
 
     const dkB = ["a_val", "b_val"].join("\0");
@@ -354,8 +370,8 @@ describe("computeAncestorRowIds", () => {
 
     const ids = computeAncestorRowIds(selection, rows, rowDimensionNames);
 
-    expect(ids.has("1")).toBe(true);
-    expect(ids.has("1.0")).toBe(false);
+    expect(ids.has(buildExpandKey(["a_val"]))).toBe(true);
+    expect(ids.has(buildExpandKey(["a_val", "b_val"]))).toBe(false);
   });
 
   it("A (depth-0) header clicked: a depth-1 child with null value is not selected", () => {
diff --git a/web-common/src/features/dashboards/pivot/pivot-selection-indices.ts b/web-common/src/features/dashboards/pivot/pivot-selection-indices.ts
index a9fa8c6fab4..71552c25e4f 100644
--- a/web-common/src/features/dashboards/pivot/pivot-selection-indices.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-selection-indices.ts
@@ -8,6 +8,7 @@
 import type { HeaderGroup, Row } from "tanstack-table-8-svelte-5";
 import type { PivotClickSelectionState } from "./pivot-click-selection";
 import { dimKeyFromRow, nestedDimKeyFromRow } from "./pivot-click-selection";
+import { parentExpandKey } from "./pivot-expand-keys";
 import type { PivotDataRow } from "./types";
 
 function selectedColumnHeaderFilters(
@@ -215,10 +216,10 @@ export function computeAncestorRowIds(
     const selectedDepth = selectedDepthByDk.get(dk);
     if (selectedDepth === undefined) continue;
     if (row.depth !== selectedDepth) continue;
-    let id = row.id;
-    while (id.includes(".")) {
-      id = id.substring(0, id.lastIndexOf("."));
+    let id = parentExpandKey(row.id);
+    while (id !== "") {
       ancestorIds.add(id);
+      id = parentExpandKey(id);
     }
   }
   return ancestorIds;
diff --git a/web-common/src/features/dashboards/pivot/pivot-utils.ts b/web-common/src/features/dashboards/pivot/pivot-utils.ts
index 7be4af5a963..437c64fe8f5 100644
--- a/web-common/src/features/dashboards/pivot/pivot-utils.ts
+++ b/web-common/src/features/dashboards/pivot/pivot-utils.ts
@@ -2,6 +2,7 @@ import {
   itemsInTag,
   type TagIndex,
 } from "@rilldata/web-common/components/menu/tag-utils";
+import { buildExpandKey } from "@rilldata/web-common/features/dashboards/pivot/pivot-expand-keys";
 import { getValuesForExpandedKey } from "@rilldata/web-common/features/dashboards/pivot/pivot-expansion";
 import {
   createAndExpression,
@@ -603,24 +604,16 @@ export function getValuesForFlatTable(
   tableData: PivotDataRow[],
   rowDimensions: string[],
   rowId: string,
-  hasTotalsRow: boolean,
 ): string[] {
-  let index = parseInt(rowId, 10);
-  const dimensionValues: string[] = [];
-
-  if (hasTotalsRow) index = index - 1;
-
-  const row = tableData?.[index];
-  if (!row) return dimensionValues;
-
-  // For flat tables, collect all dimension values in order
-  rowDimensions.forEach((dim) => {
-    if (dim in row) {
-      dimensionValues.push(row[dim] as string);
-    }
-  });
+  const row = tableData?.find(
+    (candidate) =>
+      buildExpandKey(rowDimensions.map((dim) => candidate[dim])) === rowId,
+  );
+  if (!row) return [];
 
-  return dimensionValues;
+  return rowDimensions
+    .filter((dim) => dim in row)
+    .map((dim) => row[dim] as string);
 }
 
 /**
@@ -636,7 +629,7 @@ export function getValuesForFlatTable(
  * merge config.whereFilter themselves.
  *
  * Every public getFiltersFor* function delegates here after extracting its
- * dimension entries from whichever data source it uses (positional rowId,
+ * dimension entries from whichever data source it uses (value-based rowId,
  * direct rowData, column header path, etc.).
  */
 export function buildPivotFilter(
@@ -673,28 +666,16 @@ export function getFiltersForCell(
   tableData: PivotDataRow[],
   upToDimensionIndex?: number,
 ): PivotFilter {
-  const { rowDimensionNames, measureNames, isFlat } = config;
-  const hasTotalsRow =
-    config.pivot?.showTotalsRow !== false && measureNames.length > 0;
+  const { rowDimensionNames, isFlat } = config;
 
   let values: string[];
   if (isFlat) {
-    values = getValuesForFlatTable(
-      tableData,
-      rowDimensionNames,
-      rowId,
-      hasTotalsRow,
-    );
+    values = getValuesForFlatTable(tableData, rowDimensionNames, rowId);
     if (upToDimensionIndex !== undefined && upToDimensionIndex >= 0) {
       values = values.slice(0, upToDimensionIndex + 1);
     }
   } else {
-    values = getValuesForExpandedKey(
-      tableData,
-      rowDimensionNames,
-      rowId,
-      hasTotalsRow,
-    );
+    values = getValuesForExpandedKey(tableData, rowDimensionNames, rowId);
   }
 
   const rowEntries = values.map((value, index) => ({
diff --git a/web-common/src/features/dashboards/pivot/types.ts b/web-common/src/features/dashboards/pivot/types.ts
index 1385180dcba..18eb539215c 100644
--- a/web-common/src/features/dashboards/pivot/types.ts
+++ b/web-common/src/features/dashboards/pivot/types.ts
@@ -65,7 +65,7 @@ export interface PivotState {
   totalsRowPosition?: PivotTotalsRowPosition;
   rowLimit?: number;
   outermostRowLimit?: number; // Local limit for outermost dimension only
-  nestedRowLimits?: Record<string, number>; // Local per-row limits keyed by expand index (e.g., "0.1.2")
+  nestedRowLimits?: Record<string, number>; // Local per-row limits keyed by value-based row id (see pivot-expand-keys.ts)
   // Per-measure conditional formatting, keyed by measure name. Measures not
   // present here render without any cell formatting.
   measureFormatting?: Record<string, PivotMeasureFormatting>;
diff --git a/web-common/src/features/dashboards/proto-state/fromProto.ts b/web-common/src/features/dashboards/proto-state/fromProto.ts
index f98d8ecf9c4..c28f26871ff 100644
--- a/web-common/src/features/dashboards/proto-state/fromProto.ts
+++ b/web-common/src/features/dashboards/proto-state/fromProto.ts
@@ -460,7 +460,8 @@ function fromPivotProto(
       ...colDimensions,
       ...dashboard.pivotColumnMeasures.map(mapMeasure),
     ],
-    expanded: dashboard.pivotExpanded,
+    // Expanded rows are runtime-only, not restored from saved dashboard state.
+    expanded: {},
     sorting: dashboard.pivotSort ?? [],
     columnPage: dashboard.pivotColumnPage ?? 1,
     rowPage: 1,
diff --git a/web-common/src/features/dashboards/stores/dashboard-stores.ts b/web-common/src/features/dashboards/stores/dashboard-stores.ts
index 20351c49099..018130c9f9e 100644
--- a/web-common/src/features/dashboards/stores/dashboard-stores.ts
+++ b/web-common/src/features/dashboards/stores/dashboard-stores.ts
@@ -346,7 +346,6 @@ const metricsViewReducers = {
         }
       }
 
-      exploreState.pivot.expanded = {};
       exploreState.pivot.rows = dimensions;
     });
   },
@@ -371,7 +370,6 @@ const metricsViewReducers = {
           }
         }
       }
-      exploreState.pivot.expanded = {};
       exploreState.pivot.columns = value;
     });
   },
@@ -380,7 +378,6 @@ const metricsViewReducers = {
     updateMetricsExplorerByName(name, (exploreState) => {
       exploreState.pivot.rowPage = 1;
       exploreState.pivot.activeCell = null;
-      exploreState.pivot.expanded = {};
 
       if (value.type === PivotChipType.Measure) {
         exploreState.pivot.columns.push(value);
@@ -412,7 +409,6 @@ const metricsViewReducers = {
         ...exploreState.pivot,
         sorting,
         rowPage: 1,
-        expanded: {},
         activeCell: null,
       };
     });
diff --git a/web-local/tests/explores/pivot.spec.ts b/web-local/tests/explores/pivot.spec.ts
index 188cedc5997..c12cea087d2 100644
--- a/web-local/tests/explores/pivot.spec.ts
+++ b/web-local/tests/explores/pivot.spec.ts
@@ -742,3 +742,83 @@ test.describe("pivot run through", () => {
     await validateTableContents(page, "table", expectSortedDeltaCol, 4);
   });
 });
+
+test.describe("pivot expansion persistence", () => {
+  test.use({ project: "AdBids" });
+
+  // Expanded rows are keyed by dimension values, so they survive config
+  // changes that keep the same rows.
+  // https://github.com/rilldata/rill/issues/9781
+  test("expanded rows survive adding a measure, sorting, and a refresh", async ({
+    page,
+  }) => {
+    test.setTimeout(45_000);
+    const watcher = new ResourceWatcher(page);
+
+    await gotoNavEntry(page, "/metrics/AdBids_metrics.yaml");
+    await page.getByRole("button", { name: "switch to code editor" }).click();
+    await watcher.updateAndWaitForDashboard(pivotDashboard);
+    await gotoNavEntry(page, "/dashboards/AdBids_metrics_explore.yaml");
+    await page.getByRole("button", { name: "Preview" }).click();
+    await page.getByRole("link", { name: "Pivot", exact: true }).click();
+
+    const rowZone = page.locator(".dnd-zone.horizontal").nth(0);
+    const columnZone = page.locator(".dnd-zone.horizontal").nth(1);
+    const totalRecords = page.getByLabel("Total records pivot chip", {
+      exact: true,
+    });
+    const timeMonth = page.getByLabel("Time pivot chip", { exact: true });
+    const addRowField = page
+      .getByRole("button", { name: "Add filter button" })
+      .nth(1);
+    const addColumnField = page
+      .getByRole("button", { name: "Add filter button" })
+      .nth(2);
+
+    // Rows = Time (month) > Publisher, columns = Total records.
+    await dragPivotChip(page, totalRecords, columnZone);
+    await dragPivotChip(page, timeMonth, rowZone);
+    await addRowField.click();
+    await clickMenuButton(page, "Publisher");
+    await expect(page.locator(".status.running")).toHaveCount(0);
+
+    // Expand a month; a nested publisher row becomes visible.
+    await page.locator("td").filter({ hasText: "Jan" }).first().click();
+    await expect(page.locator(".status.running")).toHaveCount(0);
+    await expect(
+      page.locator("td").filter({ hasText: "Facebook" }).first(),
+    ).toBeVisible();
+
+    // The nested row must stay visible after adding a measure.
+    await addColumnField.click();
+    await clickMenuButton(page, "Sum of Bid Price");
+    await expect(page.locator(".status.running")).toHaveCount(0);
+    await expect(
+      page.locator("td").filter({ hasText: "Facebook" }).first(),
+    ).toBeVisible();
+
+    // And it must stay visible after sorting by a measure.
+    await page
+      .locator(".header-cell")
+      .filter({ hasText: "Total records" })
+      .first()
+      .click();
+    await expect(page.locator(".status.running")).toHaveCount(0);
+    await expect(
+      page.locator("td").filter({ hasText: "Facebook" }).first(),
+    ).toBeVisible();
+
+    // And after a data refresh: a wider time range re-queries every row but
+    // still includes January.
+    await interactWithTimeRangeMenu(page, async () => {
+      await page.getByRole("menuitem", { name: "Last 12 Months" }).click();
+    });
+    await expect(page.getByLabel("Select time range")).toContainText(
+      "Last 12 Months",
+    );
+    await expect(page.locator(".status.running")).toHaveCount(0);
+    await expect(
+      page.locator("td").filter({ hasText: "Facebook" }).first(),
+    ).toBeVisible();
+  });
+});