title: Binding property with parent ViewModel
body: <p>Please refer to <a href="https://stackoverflow.com/questions/1026342/how-can-i-tell-my-datatemplate-to-bind-to-a-property-in-the-parent-viewmodel/18717026?noredirect=1#comment27579086_18717026">How can I tell my DataTemplate to bind to a property in the PARENT ViewModel?</a></p>
  
  <p>I have similar problem... But this solution didn't work for me. I have a MainViewModel which has an observable collection of another view model say View1/ViewModel1. This view has a tree control and I need context menu for the tree. My main view has a menu. Those main menu and context menu are connected. So how can I bind the context menu commands to the main viewmodel's properties?</p>