Use data in a column from a Reference in a formula

I have a table call Tags. In the Tags table is a column I used to type in the Dept by hand. Then I had a formula in another column that would look at the contents of the string in that Dept cell and do something: $Tag if $Dept == “IX” else “” It worked fine.
Trying to be smarter, I created a table called Departments with IX in it (amongst others) and linked Tags by a reference to it. But it broke my formula (well, the cell is now blank) in Tags. The reference list item is not ‘found’ by my old formula looking for a string. How can I grab the cell contents as a string in my current formula? Thank you

A reference lookup will solve your problem. You can read about it here. The abridged version, the formula is $RefColumn.FieldToLookUp

In your case. $Tag.Dept.

Welp, that did it. I really thought I tried that but when I just tried it worked. It was a long Friday - that might be the issue. Thank you! And, it was $Tag if $Dept.department that did it for me. Not sure why I screwed that up on Friday.