Google+ like features

I was a huge fan of Google+ and this by far the closest do anything I have been on since Google+. It has been many years since Google+ shut down so my memory is a little fuzzy.

Google+ had a feature called Circles which were closed user groups. Can communities be walled off? I noticed there were some initial invite only communities that that ASF started. Can anyone have an invite only group?

Collections was another feature that I enjoyed but to be honest I am not sure how it worked.

Anyway great job in putting this together!