EDMCS Custom Validation: Block duplicate nodes within the same hierarchy tree

Summary:

I am looking for the recommended best practice or expression logic to prevent duplicate nodes within the same hierarchy tree while allowing shared nodes across different hierarchy trees.

Content (please ensure you mask any confidential information):

Use Case & Requirements:

• Allowed: Node A exists under Hierarchy Tree 1 (Root 1) AND Hierarchy Tree 2 (Root 2).
• Blocked: Node A exists twice anywhere under Hierarchy Tree 1 (Root 1), even under different parents.

Current Setup & Issues Encountered:

• Both top-level hierarchy roots currently reside within the same Hierarchy Set / Viewpoint.
• Attempt 1 (boundLocations.count(...)): Attempted to filter the location count by matching top-level ancestors (boundAncestors.get(-1).name), but collection/ancestor path properties are not accessible on the