Possible xschem/ngspice weirdness #2: net voltages don't seem to be annotatable at lower levels of hierarchy if the net exists at a higher level. In the screenshot, nodes vim and vom do not annotate properly in the subcircuit, but do annotate at the top level. I took care to save the specific subcircuit nodes: .save V(x1.vim) V(x1.vom), but the spice_probe.sym instances do not annotate at that level. This only seems to be true for the nodes which exist across hierarchy.

This is a known behavior, In spice sims nets exist only at the highest hierarchy. The reason is that the circuit is flattened before simulation by spice simulators. If you have a top level net 'A' that propagates to subcircuit 'X1', port 'B' then A == X1.B, but in simulator .raw file only A does exist.

Okay. Thanks Stefan.

Yes this issue can be solved. A hierarchical node must be resolved following ports up to the top most level. May be some day i will work on this. It is not difficult but requires to open and process all parent schematics, so it is a bit inefficient.