is anyone aware of how to make one custom list field on a record display only the values in another custom list field on the same record?

@al3xicon From what I know, you need a link between the two lists so that the values in the list can be filtered. You might have to convert the list to records first. Then add a field to each record which will be sourced from the other list. Then on the actual body fields, filter using the lists. Hope I understood your question.

I think you're right on...I appreciate the suggestion. I think I can get away with a script validation instead here, but if the users complain enough I'll look into this solution. Thanks again!

No problem. Yes, it takes a lot of manual setup so I understand the wanting of a script, haha. Good-luck.

Right - and I already have a script in place doing other validations, so it's a small lift anyway