I’m currently studying the problem and will get back to you with a detailed response once I have a complete understanding of it.

Interesting: https://ci.una.io/docs/service.html#bx_channels-entity_parent But I still don't understand what the two html blocks are for. entity_parent and entity_childs

We've been very satisfied with using Spaces to create a hierarchy for communities. We started off using Channels but the hashtags left too much room for content violations. Spaces has been a great way to create communities and sub-communities. The lone hiccup is the Roles association where we can create roles within Spaces which are independent of User Levels. We're still working through that redundancy.