Re: Creating sub social network / nings
I mean it’s not possible to have totally separate BP networks running on separate subdomains but using the same installation of BuddyPress.
If you take my suggestion, you can make groups either Private or Hidden. If a group is private, the only people who are able to read or contribute to the group are those who have either had a membership request accepted, or those who have been invited. Hidden groups are the same, but they don’t show up in group directories, and thus it’s impossible to request membership to them – you can only join by being invited.
In this way, the activity that happens in a hidden group is only viewable by members of that group. Users of the site, however, could be members of multiple groups, and could interact with each other outside of those groups, through the profile pages and private messaging (assuming that you enable these features). From my point of view, this is the best of both worlds.