Fields are a great way to label elements but for coordinates you can only take the absolute values.
On site we (and Ii guess everybody) use Floorplans for assembly. Imaginge you have a building with several floors. Each floor on another file so when referenced identical you get the complete building model - as it should be - and has its own ACS.
There are objects in each floor that I need to label the lower edge relative to the top of the floors surface. This will be for any given object in an industry builing. HVAC, lighting, switches raceways.
On the ground floor model (Z=0.000) I use a simple text as label and the Z-Value as field of that text itself (e.g. "Lower Edge= 3.200 mm")Now when I move the text to the lower edge of my object. So when I move that text the height labeling goes with the height and the labeling is always correct as long as the text is on the same height as the lower edge of my object.
But on the first floor I would need to also like to use the same way of labeling. But I am stuck with the absolute Z-Value.

I need a way to calculate within a field so I can get my field to show the height of objects relative to the bottom of each floor