The key concept is that the FBI used the FISA request on Page to be able to surveil anyone on the Trump campaign, including, it can be assumed, Candidate/Nominee/President Trump.
But unless such extra surveillance revealed crimes committed, the FBI has never revealed who else was surveilled other than Page.
That brings us to the next obvious question for appropriate FBIers to be asked: Who else, other than Carter Page, was surveilled under the FISA Court approval obtained for Carter Page?
Exactly, and since the actual listening to the (recorded) conversations is a rather lower level SA job or even a non-agent ‘civilian’ job, accomplished by people with no probable malintent, they will probably tell all they know... or at least one will.... and that’s all you need!