How to generate a mirror copy

How to generate a mirror copy of a model, that is, I have a part with a left slot, when making a copy of this it is possible that the slot is on the right to obtain a part with a right slot and another on the left within the same component

To mirror an item within a DC, you must first assure there is a sub with at least one active attribute within the item to be mirrored, then you would change the sign of the size in the mirror direction.
The attached DC of a cupboard includes the copy function as well, so a pair of doors can be left and right swing.
At the door level, the simple line handle is a group that has the minimum active attribute being visibility. hidden set to false. Then the sign of lenX of the door is change as per the option and whether it is an even or odd copy
There is a current bug with this example in that the doors need to be closed before changing the number, otherwise the change effects the swing, however this rectifies on animation.
door example (2).skp (55.7 KB)

On rereading your question, you mention a “slot” , would that be a cutting component? if so then the internal copies need to be contained within another cutting component for the copies to cut. If you load your example file I can show you how it is done.

Thank you very much for your answer, yes of course it would be interesting to know how it is done with cutting components, I still do not have a model, I just want to know how far I can go before I start and thus not have to repeat worklat example.skp (21.5 KB)

Hello, I would like to know if it is possible to add a tolerance between the doors to your model, and if so, thank you very much

Added clearance and gap attributes, is this what you mean?

door example (2).skp (81.5 KB)

the groove would be better created with solids
panels with grooves.skp (168.0 KB)
#1, via subtraction
#2, via union or outer shell
#3, via cuts and explode, however can not use for through slots.
#4, shows subtraction can be used for complexity with less coding.

all can be manually simplified, but have attributes that can be used via script in one simple click

what line of work will that be?

Yes that’s excellent, thank you very much, you are the best, I take off my hat and the best thing about you is that you are a great person who shares his knowledge with the rest of humanity once again, thank you.