Sorry, Sure. Thank You Arsalan.

@Bala please create different topic as this didn't relates to this.

Is there a way in the DB to find out from which user referral/invite did his/her friend join?

If UserA invited UserB, and if UserB registered, do we know in the system that UserB joined because of UserA?

Please help. We need some reporting.

Idea:
Whenever a friend request is either made or confirmed the function ossn_add_relation will be called.
At the bottom of this function a callback will be triggered - which is providing the user guids of both members involved.
That's your starting point. The rest ('friendship confirmed' notification) would be very much similar to the already existing 'friendship requested' notification.