I want to implement the add friend functionality, for this I need a user id, but how do we see who is online? Is it possible to have some users pre assigned to a group or organization or something similar, and grab those users as if they were friends ?

Lets say my app belongs to customer x , and customer x has 2 groups, the jedis and the dungeoneers, how would I make so the users in jedis only see the users there and users on dungeoneers only see users there.

Not sure if possible, but very curious about this functionality. I hope all of that made sense.