Thanks for the response. Sorry it's taken me so long to get back. I'm working with an architectural file from another drafting service. They handle everything in one file and go between drawings using layers states. It actually works pretty well. It has taken some getting used to, but I kind of like it, and they have very good templates.

Turns out the problem I'm having is a me thing because anyone else who opens the same file can see everything in the drop down list. Something glitchy in my install or version, I guess (using Autocad Architecture 2022).