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 :

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