I am pretty sure that is the correct way to do it. One thing to be aware of though, the term "group" in liferay is normally how you refer to a "site". Just wanted to share that (in case you weren't aware) so that if you post in the forums again in the future you're using the same terminology the community is used to. Otherwise, you might end up getting odd responses 
Hi Diego,
That's true, but don't forget that individual users can be assigned to "communities" (now referred to as sites) as well. So I would say that your train f thought is definitely correct, but you can also, in a way, group users under sites. You also have to remember that content is scoped by site as well. So really, a community or site as it is now referred to (starting in Liferay 6.o or 6.1 I believe) is a mechanism for grouping assets and some settings into a scope that is one level lower than a portal instance. I can have User A and User B assigned to Site A ... and User C assigned to Site C. I can use this mechanism (in the API) to group users -- but it's a pretty silly way to do it of course, and we should use User Groups and Roles for such things.
That's true, but don't forget that individual users can be assigned to "communities" (now referred to as sites) as well. So I would say that your train f thought is definitely correct, but you can also, in a way, group users under sites. You also have to remember that content is scoped by site as well. So really, a community or site as it is now referred to (starting in Liferay 6.o or 6.1 I believe) is a mechanism for grouping assets and some settings into a scope that is one level lower than a portal instance. I can have User A and User B assigned to Site A ... and User C assigned to Site C. I can use this mechanism (in the API) to group users -- but it's a pretty silly way to do it of course, and we should use User Groups and Roles for such things
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