Pick edge in linked file - Is it possible?

I would link to know is anyone in this forum can come up with at way of selecting an edge in a linked file? I can only find a way for selecting an element, point or surface in a linked file.
I am trying to have my facade adapt to a roof edge located in a linked file.

If you can get the surface then you already have the edge. Extract it form the surface.

Try extruding the surface or the edge line over the surface you want to pick, inside the link’s software and load it back again to revit. this way i think an edge can be selected.