Ability to hide/display federated search results by user group

In our case, we are especially interested in hiding those results to guest users, but I think this as a setting could be interesting more globally and give the ability to select which users should be able to see or not federated search results.

In our case, we've made our community hybrid in visibility; most community categories are only available to registered users.

We would like to hide federated search results from non-logged in users as it is mostly documentation for staff (who are our registered users).