@TIG No, Dezmo's code makes everything unique (one single instance for each object), but this is what I asked him for.
Eneroth extension is the only one that does what logically it is supposed to do in this command - no matter the number of nested levels, no matter the type of objects (groups or components - yes, I made a mistake in the previous reply.!), whatever you select, Eneroth unlinks all of them from the rest of the model, but keeps all the relations between them in your selection, with the same structure of nesting.
I mean the same thing that SU does when you select some non-nested components and make them unique, but it is doing the same thing in whatever nested combination of groups and components. All other extensions that pretend to do this... just create a mess in your nested structure, especially if you mix them up (components inside groups...).
I asked to Dezmo for one command that breaks everything (groups) to the last object because I couldn't find anything reliable, I mean the only one reliable is 3DS House extension, but that one requires internet to open its UI, and sometimes I'm in places that for short periods I don't have internet.
I hope Dezmo (or somebody else) can do the Families selection also for groups, because mine works only for components; that one I found it on VBO Facebook page.