We have a connected board via the connect board column.
To each element on board X we assign a different element from the second board Y (connect board).
When selecting connect element Y, allow selecting only subelements of Y and not all elements on board A, B, C. The team should be able to assign a subelement of a higher element and not all subelements. This causes terrible errors - when the employee connects element A and a subelement from element B or C