Thanks Emily. What i need is to not filter both datasets. I only want to filter on one of them. But since they are linked, they both get filtered.
Ah, got it. I haven't run into that issue before. I wish I knew an answer.
If no one else responds with an easy fix, I would just merge the two data sets outside of Tableau and import the new, combined spreadsheet/csv/whatever so you can have more control of it. Pain in the ****, I know, but it might be worth a shot.