You want to use a simple equal sign. This does a “Text equality, permutation” comparison. So “A”:”B”:”C”=”B”:”C” is True, which is exacly what you are looking for. Look up “Operations on lists” in Notes Designer help.
You can set up a dynamic table to display information from the associated records. I need to do the exact same thing for a case tracking system. I already do this in multiple areas, showing all linked SARs for a case in a dynamic table, etc. Let me know if you want to know more about the dynamic table.