Adding/Removing Records from a Junction Object Table from the Lookup Object Table

I previously had a use case with a junction object, where our end users also had to create records in the lookup object before creating the junction object record. After some time, I’ve realized we need to improve the UI for this process. Here’s the previous thread:…

What I would love to do is the following:

Table A = lookup object, which looks up to the Account
Table B = junction object, looks up to the Opportunity and Table A

  1. Have user create record in Table A table (only two fields to be filled out)
  2. Row action on Table A that creates a record on Table B - I can currently do this already (once the record on Table B exists, the row action won’t render for that Table A record - i.e. no duplicates)
  3. Row action (or some other way) on Table A that queries any records on Table B that looks up to the Table A record, and deletes that Table B record (this is the tricky part)
To give an example of how this would work:
  1. Create 2 records on Table A with the fields Name and Channel (ESPN, Web; ESPN app, iOS)
  2. Add both records to Table B using the row action button
  3. Remove the iOS App from Table B using the row action on Table A
Finally, Table A would have 2 records, ESPN and ESPN app. Table B would have one record: ESPN. We also would not have the ability to create a new Table B record for ESPN, but would for ESPN app. Ideally, we could also highlight the ESPN record on Table A to show that it “exists” on the Table B record.

How might I go about doing this? I’ve been trying for the last few days and can’t seem to find a solution without making Table B visible, which has caused confusion for our sales team.

Also please let me know if this isn’t clear.