Thanks for posting the model.

So yeah if I take your chair model and make some copies it looks like this:



You've got the duplicate names there that you don't want - like "Foot rest" for example is the same name on all 3 foot rests.

But why at this point in your screencap are you selecting the copied objects and setting all their names to something like "chair1" ? That is not making a hierarchy - what that is doing is erasing all the existing names on all the selected objects and instead setting them to have the name "chair1".

It doesn't seem like you want to do that - you're erasing all your assigned names by doing that.

Instead right after copying, run the script (do not assign any new names), and the object names will separate like this:



So now you've got different names for each foot rest - the foot rest for object 1 is "Foot rest_1", the foot rest for object 2 is "Foot rest_2", and the foot rest for object 3 is "Foot rest_3".

Doesn't that do what you need?

- Michael