Custom Control Binding to Command in Parent View Model?

I have a custom control within a ContentView and I would like the ability to Bind to a Command in the Parent View Model.
Is this possible, does MyContentView inherit from the Parent Page?

My design is as follows:

1. MyPage.xaml ( BindingContent is MyPageViewModel )
2. within the XAML page I have created a child view -> local:MyContentView
3. and within the child view is a custom control -> local:CustomButtom

Within CustomButton.cs I have the following bindable properties

    public class ToggleButton : ContentView
     {
        public static readonly BindableProperty CommandProperty = 
                          BindableProperty.Create("Command", typeof(ICommand), typeof(ToggleButton), null);

        public static readonly BindableProperty CommandParameterProperty =
                          BindableProperty.Create("CommandParameter", typeof(object), typeof(ToggleButton), null);

    public ICommand Command 
    { 
    get { return (ICommand) GetValue(CommandProperty); } 
    set { SetValue(CommandProperty, value); }
    }

    public object CommandParameter
    {
    get { return GetValue(CommandParameterProperty); }
    set { SetValue(CommandParameterProperty, value); }
     }

and to execute the Command I use this

if (Command != null)
{
Command.Execute(CommandParameter);
 }

However when I add debug break point to the above 'if' statement
Command is always null and does not Bind to the Command in the Parent ViewModel