If in the Enter Value field (or an adjacent component), you had the ability to select a tabsheet and a column, similar to the add columns in the Data section Relation dialog. The developer could have a tabsheet with a bunch of columns, with data that would have application wide scope adding variable sheet data into the developer. This would allow those values to be dynamic, by using formulas that are controlled by sheet logic.
I use this technique now in my scripts so my scripts don’t need to be changed because a the info is not hard coded in the script. The scripts are more portable and in some cases multi purpose. I store URL’s and sheet ID’s, next unique ID numbers (for shortened style UUID for relationships between sheets) and any choices for dropdowns. In this case you would only pull back the contents of row 2 for that column but you get the idea I hope. It would greatly expand the capabilities of the filter.