Controlling asset dependencies in large Unreal projects is critical to avoiding “spaghetti dependencies”, inflated cook times, and broken builds. The Asset Reference Restrictions system (often referred to as Asset Referencing Policy) provides a framework to define boundaries between folders, plugins, and core project content. It actively filters the Asset Picker UI in the Editor and integrates directly with the Data Validation pipeline.
https://dev.epicgames.com/community/learning/tutorials/7xPbn/unreal-engine-controlling-dependencies-with-asset-reference-restrictions