Linking Gadget via custom fields

I've created cross-database views (Connected Tables) and actually created new Views on Primary Entities (cross database). Then I've used this to create Reports, and corresponding Gadgets.

The issue now is that I'm trying to link some of these gadgets so that highlighted Transactions on Gadget A show Transaction Detail Lines on Gadget B.

So, is it possible to expose the connecting field that joins these two? At this point, the only available field is the CompanyID (which is in each of the Views as it is the Primary Entity).