I'm going to move this thread from the FileMaker Community Feedback Space, which is specifically for input on the Community itself, to the Discussions Space where you should receive even more views and potentially more advice!
the relationship itself should be filtering the records you want to see. On your Concepts layout, next to the three fields you are using as criteria, place one of the child key fields from the related table (I color these green). This will immediately show you if your relationship is working.
Also, Count(relationship::PrimaryKey) > 0 will indicate a positive match.
How can I display Count(relationship::PrimaryKey) > 0? Maybe with Insert Other Symbol??
The problem regarding the filtering was that the date range was specified by global fields in the Concepts table --- I think!!
you'd need a calculated field for that, or some version. You're better off making sure that you can see the three fields used in your relationship in the parent table layout, and any field (preferably a primary key) in the child table. It's just a proof of concept.
You can use the Count function in scripts to make sure that there are child records to assess.