How to Link Records Through Their Line Items?

I'm currently using Unifier Version: 23.4 b-03272023-04

I'm trying to make one record's detail form be auto-updated from populating the detail form of a record in a different BP.

For example, lets say you have one BP that tracks names and addresses, aka BP 1. You have another BP that tracks properties, aka BP 2.

BP 1 has a line item detail form to track what properties that person has a relationship to, whether they be an owner, tenant, etc. BP 2 has a line item detail form to track the people that have a stake in that property, whether they be an owner, tenant, etc.