I'll try to be clear, is it possible to start a 7.1 location for example.
In a head assembly I have a sub-assembly that carries rep 7 and therefore these components 7.1, 7.2, etc.
I want to make the drawing of this sub-assembly mark 7, and I would like the nomenclaure to be identical to that of the plane of the head assembly, i.e. 7.1, 7.2, etc.
Otherwise, intermediate solution, you need to create a property, for example "marker", in your rooms and set and create a nomenclature that will remind you of this property.
This way, each element will always have the same marker, regardless of the plane, with the value you want. On the other hand, you have to manage the markers yourself and enter them by hand in each element.