Tabbed fragement access data other fragment


I am trying to ‘reuse’ a recyclerview. I have a tabbed fragment (contacts) with a list of contact (contactsList). On another tab I have a fragment called group with a FAB that activates a new activity (addGroup). On that addGroup activity I have copied (included) the same Recyclerview as on the contactsfragment. I’d like to multi select a couple of contacts there.

I am able to set the Recyclerview up, the only problem is that I am missing the adapter from the contactsList. I’d like to add the adapter on the activity to the one that is one the tabbed fragment. But how do I share data between a tabbed fragment and an activity on another tabbed fragment?