BuddyCircles:- The BuddyPress User Circles plugin is an add-on for BuddyPress. It allows users to create lists of users, e.g. Family, Close Friends, Colleagues, etc.

Features:-​

• Allow users to create circles of users(or lists of users).
• Filter activity by circles.
• Circle notifications.

And here is a list of all features for site admins:-

• Limit circle creation by roles.
• Configure if the circle will be a top-level tab or be managed under the friends component.
• Restrict who can be added to the circle:- Friends or all members.
• Control circle privacy.
• Automatically create default circles for newly registered members.
• Control notifications for add to circle or remove from the circle.
• Customize notification emails.

BuddyCircles is most suitable when you want your users to have the ability to create multiple lists of users and optionally follow their activity.