You can plot STATUS variable on undeformed model to visualize the cutting depth. Another useful output variable to display on contour plot in this case is COORD. This one stores current (when NLgeom is ON) coordinates of integration points or nodes of each element. Just choose the nodal one and proper component (in the depth direction). You can also create custom field output using COORD (and other variables if necessary). It can be done using Tools —> Field Output —> Create From Fields. There it’s possible to operate on field output variables to create new ones.