Configure which groups see another group

We’re looking to create more Facebook-style groups (hate to compare it to that, sorry) where members of those groups effectively get their own sub-forum, chats, etc. So, folks will need to be able to request membership into specific groups in order to gain access to those areas. Full discussion on the topic below:

I understand there is core functionality coming on this at some point, and I’m hoping it is nice because if we can’t get this working in our community there is a good chance we’ll need to move to a different platform. The socialization/group aspect of our community is super important to our growth plans.