in general CM&C uses connectivity to map your circuits.
As an example you have two identical circuits, e.g. two voltage regulators in your design.
When you want to use CM&C here, layout the first one, then selct it by CMC and paste.
Now the wizard recognices, that you overall netlist has a similar circuit (different RefDes and Net names) with
same connecitivity. It automatically identifies it and mekes a proposal which parts and nets to map.
This all is based primary on connectivity and part names.
When the part names are different, it will not be able to map in most cases.
You mentioned, you tested unplace.
This is not necessary, because connectivity will not change.
You can use the CM&C Selection List to review which components you copy and remove unwanted in this dialog.
There is no way to use net names as a rule. It is all connectivity driven.
But the wizard alows you to map manually other components and nest, if they fit.