Friends functionality and filtering the Create Group Channel user list

[Problem/Question]
We have rules in place in our app to determine what users can start conversations with each other. I was wondering if there is functionality where I can send these relationships to sendbird to affect screens like the Create Group Channel fragment that appears to show all users registered in the application or if we have to manage that outside of sendbird and filter the user list that is used to generate that screen? Are there examples of this type of scenario somewhere that we could look at? Initially I thought that is how the discovery_keys collection on a user profile was intended to be user, but it doesn’t appear to work in that manner.