I have a page with multiple controllers, one of the controller is being used in 2 different divs within the same page. I am not sure if it is a scope issue or I just miss someth
Same controller, but declared twice. therefor - two scopes.
Normally the solution is to move the ng-controller declaration one dom level higher (in your case, to the body element. once only), and have it only once. Otherwise, look into angular services.
see updated plunkr: http://plnkr.co/edit/pWnx2mdMeOeH33LUeTGm?p=preview