You might take a look at this session video where she goes over working with content from Reality Composer Pro in Xcode (https://developer.apple.com/videos/play/wwdc2023/10273/?time=1818) including materials (toward the end of video).
And the Diorama sample code is available here (https://developer.apple.com/documentation/visionos/diorama), which also might be helpful, specifically the DioramaView where the RealityKitContent is loaded and how they navigate the hierarchy of the Reality Composer Pro scene.
Topic:
App & System Services
SubTopic:
Core OS
Tags: