Lookup table to filter by repeat group number

Hi, I'm trying to do a very simple thing in theory. I have a lookup table that has a column "grant" and a question "donor", I want to have it filtered by the answer. It works fine until I try adding new repeat groups. It then basically gets lost and can't find the correct "donor" question in a list of nodes. I spent this whole day trying to feed it group numbers as indexes, but it just fails to count, always resulting in 1 and selecting the answer in the first group. Sometimes, in this case if I write position(../..), which as far as I understand should give me the position of recipient, it says that / is empty.
Is there a simpler way or any way to do it?

P.S. When I made a couple of questions with calculate conditions such as position(..), position(../..) etc. I was getting the expected behavior - it was incrementing for both levels. Also I had no luck trying out a simple ../donor

I think I made it work using grant = current()/../donor, I was fooled by this article https://dimagi.atlassian.net/wiki/spaces/commcarepublic/pages/2143956644/Using+Repeat+Groups+in+the+Form+Builder to believe that .. = current()/..