How to combine AHTabBarController with Navigation controllers

[jeromeDms]

Hi All
I'd like to use AHTabBarController with multiple navigations controllers, basically one navigation controller per top level tab.
Sub tabs, when clicked should be able to push a new view controller to the navigation controller of the current selected tab.
I'm not using storyboards, I then used the branch where we can set the view controller using viewControllerForSubItem function.
Any advise to be able to do the above would be appreciated.
Thanks !