Return Distinct Values in a Value Set

Hi,

We have a value set that returns our position titles that is used in the document record screen, we need to update this screen to Redwood but Redwood does not allow the full list and requires it to be distinct values only.

I have tried following the note (Fusion PIM: How to show distinct values in a Table Value Set? (Doc ID 2151045.1)) to build there clause as below but it is still not restriciting the list, has anyone has a similar issue / solution?

hapft.rowid = (
SELECT MAX(rowid)
FROM HR_ALL_POSITIONS_F_TL hapft2
WHERE hapft2.position_id = hapft.position_id