Hi Steve,
Thanks for quick response. I am not sure though, if we are after same thing here.
Let's say I have two user groups - Group 1 and Group 2
I'd like to be able to allow conversations only between users which belongs to Group 1. In a same way users who belong to Group 2, would be able to communicate between each other. But user from Group 1 wouldn't be able top chat to users in Groups 2 and vice versa.