Different versions of drawing in one file

I would like to try to make a drawing with several version of some items on it.
Let say that most of the drawing is common for all version. But some portion of this drawing is different in earch version.
Is there any method of hiding some blocks or groups?
I could use layers for this purpose, but what to do if all options contains some blocks put on different layers? In this case it will not work.
I cannot also use underlays becase I would like to have a possibility of editing these versions.
Marek Staniewski

Marek wrote:
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Set everything up on different layers... draw everything in model space... then in paperspace set up different viewports - you can control what layers show (on or off) in each viewport. You don't have to do this on a single sheet of paperspace - you can create multiple paperspace tabs / pages..
Martin

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Martin
Thank you for your advises. But this is probably not that easy. Each versions contains complex blocks, which are put on different layers. Some of the blocks are common for both versions. Therefore I cannot do it simply by putting both versions on different layers.
Marek