diff --git a/src/routes/v2/pages/Editor/lineage/collectLineageUsages.test.ts b/src/routes/v2/pages/Editor/lineage/collectLineageUsages.test.ts
new file mode 100644
index 000000000..a2b749c78
--- /dev/null
+++ b/src/routes/v2/pages/Editor/lineage/collectLineageUsages.test.ts
@@ -0,0 +1,98 @@
+import { describe, expect, it } from "vitest";
+
+import { ComponentSpec } from "@/models/componentSpec/entities/componentSpec";
+import { Task } from "@/models/componentSpec/entities/task";
+import { LINEAGE_ORIGIN_ANNOTATION } from "@/utils/annotations";
+import type { ComponentLineage } from "@/utils/lineage";
+
+import { collectLineageUsages } from "./collectLineageUsages";
+
+const ORIGIN = "https://x/train.yaml";
+
+function taskWithLineage(
+  $id: string,
+  name: string,
+  digest: string | undefined,
+  lineage: ComponentLineage | undefined,
+  subgraphSpec?: ComponentSpec,
+): Task {
+  const task = new Task({
+    $id,
+    name,
+    componentRef: { digest },
+    subgraphSpec,
+  });
+  if (lineage) {
+    task.annotations.set(LINEAGE_ORIGIN_ANNOTATION, lineage);
+  }
+  return task;
+}
+
+describe("collectLineageUsages", () => {
+  it("matches by origin id even when digests have diverged", () => {
+    const spec = new ComponentSpec({
+      name: "Pipeline",
+      tasks: [
+        taskWithLineage("a", "Train A", "digest-original", {
+          originId: ORIGIN,
+          originDigest: "digest-original",
+        }),
+        taskWithLineage("b", "Train B", "digest-edited", {
+          originId: ORIGIN,
+          originDigest: "digest-original",
+        }),
+        taskWithLineage("c", "Other", "other-digest", {
+          originId: "https://x/other.yaml",
+        }),
+        taskWithLineage("d", "No lineage", "loose-digest", undefined),
+      ],
+    });
+
+    const matches = collectLineageUsages(spec, ORIGIN);
+
+    expect(matches.map((m) => m.taskId)).toEqual(["a", "b"]);
+    expect(matches[1]).toMatchObject({
+      taskId: "b",
+      taskName: "Train B",
+      digest: "digest-edited",
+      subgraphPath: [],
+    });
+  });
+
+  it("recurses into subgraphs and records the subgraph path", () => {
+    const nested = new ComponentSpec({
+      name: "Sub",
+      tasks: [
+        taskWithLineage("nested", "Nested Train", "digest-nested", {
+          originId: ORIGIN,
+        }),
+      ],
+    });
+
+    const spec = new ComponentSpec({
+      name: "Pipeline",
+      tasks: [
+        taskWithLineage("root", "Root Train", "digest-root", {
+          originId: ORIGIN,
+        }),
+        taskWithLineage("group", "Group", undefined, undefined, nested),
+      ],
+    });
+
+    const matches = collectLineageUsages(spec, ORIGIN);
+
+    expect(matches.map((m) => m.taskId)).toEqual(["root", "nested"]);
+    expect(matches[1].subgraphPath).toEqual(["Group"]);
+  });
+
+  it("returns no matches when nothing shares the origin", () => {
+    const spec = new ComponentSpec({
+      name: "Pipeline",
+      tasks: [
+        taskWithLineage("a", "A", "d", { originId: "https://x/other.yaml" }),
+      ],
+    });
+
+    expect(collectLineageUsages(spec, ORIGIN)).toEqual([]);
+  });
+});
diff --git a/src/routes/v2/pages/Editor/lineage/collectLineageUsages.ts b/src/routes/v2/pages/Editor/lineage/collectLineageUsages.ts
new file mode 100644
index 000000000..36510b6bd
--- /dev/null
+++ b/src/routes/v2/pages/Editor/lineage/collectLineageUsages.ts
@@ -0,0 +1,49 @@
+import type { ComponentSpec, Task } from "@/models/componentSpec";
+import { LINEAGE_ORIGIN_ANNOTATION } from "@/utils/annotations";
+import type { ComponentLineage } from "@/utils/lineage";
+
+export interface LineageUsage {
+  /** The task instance sharing the queried origin. */
+  taskId: string;
+  taskName: string;
+  /** Current component digest of this instance (differs once locally edited). */
+  digest?: string;
+  /** The instance's full lineage record. */
+  lineage: ComponentLineage;
+  /** Subgraph task names from the root down to this task (empty at root level). */
+  subgraphPath: string[];
+}
+
+/**
+ * Find every task in `spec` — recursing through subgraphs — whose lineage origin
+ * matches `originId`. This is the in-pipeline "find all usages across nesting"
+ * primitive: it keys on the stable lineage origin (not the digest), so it still
+ * groups instances whose digests have diverged through local edits.
+ */
+export function collectLineageUsages(
+  spec: ComponentSpec,
+  originId: string,
+): LineageUsage[] {
+  const matches: LineageUsage[] = [];
+
+  const walk = (tasks: Task[], path: string[]) => {
+    for (const task of tasks) {
+      const lineage = task.annotations.get(LINEAGE_ORIGIN_ANNOTATION);
+      if (lineage && lineage.originId === originId) {
+        matches.push({
+          taskId: task.$id,
+          taskName: task.name,
+          digest: task.componentRef.digest,
+          lineage,
+          subgraphPath: path,
+        });
+      }
+      if (task.subgraphSpec) {
+        walk(task.subgraphSpec.tasks, [...path, task.name]);
+      }
+    }
+  };
+
+  walk(spec.tasks, []);
+  return matches;
+}