Showing only 1 category at a time?

Maybe a stupid question, but..

Is there any way to split up the forum in categories, by showing one category at a time?
For instance, is there a url that will show me only the forums under "international discussions" in here?

For large forums with many sub-forums, it is helpful to show only 1 category at a time, as well as making it easier to understand for the users.