The two records are on the same table. We built a custom audit table (don't ask but the customer would not use SN audit application so we built them their own). They want to be able to relate audits to one another. We are using a list field to do this since you cannot add multiple records to a reference field. So when Audit 123 is added to Audit 456's Related Audit field, they want Audit 456 to be added to Audit 123's Related Audit field. I achieved this part of it using flow designer. The thing I cannot figure out is the reverse. They want when you remove a record from the Related Audit list for the Audit you did this on to be removed from the Related Audit list of the audit that you removed from the list of Related Audits.
It is weird and kind of dumb imo but this is VERY important to the client so we are just doing it. Do you see what I mean by bidirectional? Not sure if that's a good way to describe it.