Change attribute based on dublicated id

Hi all,

The image you can see the attribute table of my datasets. I would like to change the attribute position based on a logic like this

• If the position of an object is UNDEFINED, I would like to find an object that has same _id value and then if the object with same _id's position is RIGHT, assign the position value as LEFT.
• For example, the object with _id_rule 14 has position as UNDEFINED, so i would like the find the other object that has _id 11 (it is common in both object). In my case, It would be the object with _id_rule 10. Then I would like the check the position value of the object with _id_rule 10. If it is RIGHT, I would like to change UNDEFINED value to LEFT for the object with _id_rule 14

I have tried to use combination of tester & sampler but could not figure out so far. Any idea? Thanks in advance.