In side-menu-content another side-menu?

Hi, i have a left Sidemenu, which is for navigation between the main sections. Now when i go to a main section for example to customers, it’s content gets loaded in the side menu content properly.

But now it this customer Area i want to have also a right Sidemenu. But the problem is, this Sidemenu should also be in the CustomerController and not in the AppController.

Maybe this image explains a bit, the thing i want to achieve…
Somebody has maybe an idea, how i could get this to work?

PS: i already got the two sidemenus to work, but only like everyone does as part of the “AppController”. But than you have two main menus, and i want a Main Menu left and a Submenu right.