Share 'multi flatten with or without pathmapper'

Hi Trying to get GH data-trees to automatically flatten all data except their lowermost branches off course this is possible with path-mapper: {A;B;C} -> {A} or {A;B} -> {A} thing is , my trees might have one, two or three original levels, so the path-mapper needs to be remapped every time the data structure changes, which is not what I am aiming at, since this has to happen several times i…