[Theme: Graphene] using custom menus

Hello,

I am building a rugby website and am looking to build in a menu structure using my categories like so:

[header menu]Internationals —> [secondary menu]Analysis
—> [secondary menu]Trends

[header menu]Super 15 —> [secondary menu]Analysis
—> [secondary menu]Trends

It’s a very simple menu structure, but for some reason the theme doesn’t allow you to have more than one secondary menu item, so that means that each header item is unable to have it’s own respective secondary menu items.

How can i create a menu using categories that allows header menu items to have their own secondary menu items?
And not just one standard header menu and one standard secondary menu?

Thank you 🙂
http://www.outrightrugby.com