old merge way allowed way to stop duplicating a parent

Cindy Hecker

In the old merge when a child is under one parent and you are merging with a child under both parents (one parent has same ID #) there was a way to stop the extra one parent from appearing again creating one of those a child is listed twice under one parent and under both parents. But the new merge does not allow me to move that extra one parent back to the left side (old merge way) to prevent that duplicate relationship. Hope that makes sense, but I prefer not to prevent a duplicate relationship than have to go back and correct it after.