I have a wordpress multi-site install and then installed http://buddydev.com/plugins/buddypress-multi-network/ so that I could have multiple buddypress networks.
The problem is that I don’t want a user to be able to join any network they want.
For example, I have 1.[domain].com and 2.[domain].com. Each one has its own buddypress network. The problem is, even if I have the private buddypress plugin installed, if someone has an account on 1.[domain].com, then they can just login on 2.[domain].com because each is a site on the multi-site network and the user is a member of that network.
I want to make it so that the user on 1.[domain].com would need to request access to 2.[domain].com in order to use it.
So, basically what I want is for a someone to be able to set up say a private company community at 1.[domain].com and another company to set up a private company community at 2.[domain].com. I would like it so that an employee from company 1 can ONLY access 1.[domain].com and an employee from company 2 can ONLY access 2.[domain].com.
Anybody can access [domain].com though, that would not be a problem.
I'm not sure if this is of any help: http://wordpress.org/support/topic/separate-user-bases.