Single drop down show 2 different entities based on choice.

Have 2 entities which have different values for same attributes. The drop down is located in the form at position 5 ,( for example) on position 4, i make a choice which has a certain text.  So based on this choice, i would like the position 5 drop down to show from either of the 2 entity based on pattern match on position 4.. looking for ideas to solve this..
1 answers

The easiest way to do this is to have a relation with both possibilities, add two dropdowns for the position 5 selections, and use conditional visibility to hide whichever dropdown shouldn’t be used on position 5.

It’s a bit abstract without more context, but that’s the general idea.