Linking imported tables with existing id columns

I have a number of csv files that I have imported into Grist. The main file, call it table A already contains fields that contain ids for rows in table B.

Can i somehow use this id to setup references between tables A and B in Grist.

If not can I manually link the tables

I have discovered how to link the tables from the Reference Columns Guide, in the docs. However, I am finding that it isn’t filtering the referenced records. Clicking on a record in Table A, moves the record pointer to the correct record in Table B, but all the other records in Table B are also shown. All the tutorials show the records in Table B being filtered. Do I have a setting wrong somewhere.