Data and Multiple Sources

[TCArknight]

Howdy!

I am working on a dataset where items in the core book can be classified as being part of “Past Era”, “Present Era” or “Future Era”. This works fine with an Era source group and just the three selections.

My difficulty comes with sourcebooks. A sourcebook can add material to any or all of the eras. How can I make sure that an item added from a Sourcebook is only visible when the valid Era is also selected (I.e. both Past and Sourcebook 1 have to be selected for Past material from Sourcebook 1 to show)?

As it is, if an item has an Era and the Sourcebook selected, everything from the Sourcebook shows, regardless of Era.