How does one target know another saved Core Data?

I'm using multiple targets in my project and so I've created an App Group to allow both targets to read/write from Core Data. The saves happen in the second target, and if I restart the app my table display the newly saved item.


What I can't figure out though is when the other target saves a new entity, how do the NSFetchedResultsController in the primary target know to refresh the table?


I've tried catching things from NotificationCenter but those don't seem to cross targets.