Methods to "shadow" reference parts in detail drawings. 

An alternative to configurations or a display state. Some use part configurations for unique part profile and others use display states for views like for pipe spools.

This method is manual but requires no configs or states; example for a one time detail in a drawing:

1.  Create a "reference" layer set to the thinnest line, a hidden line type, and a unique color. 

2.  In the drawling design tree, locate the part you want to partially hide. Go to "Component Display Properties" and set the line to thin and hidden line type and set the layer as set up in step 1. See image below.  

3. Copy view port. Now you have two identical views. You can isolate one from the other from the design tree. See image below. 

4. Select both views by using the "Ctrl" key then Right Click (Alignment) to center the views in the horz and virt directions. See image below. 

5. In the drawing design tree, select one view and hide one of the components you don't want shown in the view. 

6. Now the reference part is now a "ghosted" over the part in focus for a detail in the correct location. See below.