displaying site-wide categories content

I've created site-wide categories such as Music, Sports, Hobbies etc.

I'd like to display these on the top menu so that within a category, all the groups, blogs etc are displayed. So far, I haven't found a way to  do that.

If that's not possible, I really don't understand the purpose of Site-Wide Categories.

Beginning Developers

Beginning Developers

This space is for newcomers, who wish to build a new plugin or to customize an existing one to their liking