When building a hierarchy in the modeller it should be possible to add new elements at a specific place on the right side of the modeller. New elements in a hierarchy will always be added at the bottom. The only chance to reorganize the hierarchy is with moving single position up and down with the arrow buttons. This is annoying if you have a dimension with more than just a few elements in the hierarchy. Basically means clicking hundred times to move several items up and down.
It is not creating the element at a specific position in the dimension. It’s about adding the “New element” from the screenshot in the hierarchy for “Europe” between “West” and “East” without having to move it up and down for ages.