Sounds like you just need a simple relationship, with a lookup field. I am presuming one table (lets call it category table) has records that look something like:
Category A, User Jon Smith
Category B, User Jane Doe
Category C, User Julie Baker
On the other table (main table), you want to select category B, and it show Jane Doe right?
If so, make a relationship, one Category Table has many Main Tables.
Proxy field is the Category, then you make a lookup field of the User. Simply display the user field on the Main table.
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Mike Tamoush
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