One menu with separate submenus?

Is it possible to create a new ‘menu’ such as ‘Relief’ and for different relief causes, have completely separate submenus for any relief cause (to show events, articles, etc., that are specific to that cause) that should happen? I imaging this should be possible but I’ve gone around the bush so many times that I can’t figure out what the way to do this is.

I do have two submenus created (tornado and tsunami) but they aren’t working how I imagined.