Searching for dropdown or search box supporting merge with (or another idea)

my project has a table and field on a form for setting the project of a task (i.e. that task belongs to a project). However, the list of projects to display in the dropdown or search box (don’t really care which but would prefer searchbox) is not a simple one query. I need to use “or” statements. I want to say, select all projects where current user is the creator OR current user is a project manager (this is a list field on the project record). I am currently doing this with repeating groups, etc using a merge with which works fine. But, neither drop down nor search box source allows for this? I thought of saying where uniqueid is in but it also doesn’t support that either. This is a single select and not multi-select. I’ve reviewed the plug ins but can’t seem to find any that match this need. Any suggestions or help would be appreciated.