[Fenris447]

Thanks to the code from above, I was able to get this working.

I had to create Simple Things for each deity category, give them their respective DeityCat tag, and then have the adjustment generate a list of those Simple Things. The adjustment pulls the tag from the chosen thing and then either hides all deities from that category OR hides everything except for that category, depending on which drop-down you use on the adjustment.

For posterity's sake, when we add new pantheons, they will need their own Simple Thing created in the same manner. See 5CFrgtPnth in the PHB - Deities.user for an example of this.

The adjustment will be in release 3.3, since 3.2 just came out yesterday.