MainActivity.cs

using System;
using System.Collections.Generic;
using System.Linq;

using MonoTouch.Foundation;
using MonoTouch.UIKit;
using MonoTouch.Dialog;

namespace TwoLayerDialog
{
  [Register ("AppDelegate")]
	public partial class AppDelegate : UIApplicationDelegate
	{
		// class-level declarations
		UIWindow window;
		UINavigationController navigation;

		public override bool FinishedLaunching (UIApplication app, NSDictionary options)
		{

			var menu = new RootElement ("Settings") 
			{
				new Section ("Test")
				{
					new StringElement("Profile", CreateSecondLayer),
				}
			};

			var dv = new DialogViewController (menu) {
				Autorotate = true
			};

			navigation = new UINavigationController ();
			navigation.PushViewController (dv, true);

			window = new UIWindow (UIScreen.MainScreen.Bounds);

			window.MakeKeyAndVisible ();

			if (UIDevice.CurrentDevice.CheckSystemVersion (5, 0))
				window.RootViewController = navigation;	
			else
				window.AddSubview (navigation.View);
			
			return true;
		}

		public void CreateSecondLayer()
		{
			var root = new RootElement ("Second") {
				new Section (){
					new BooleanElement ("Airplane Mode", false),

				}
			};

			var dv = new DialogViewController(root, true);
			navigation.PushViewController(dv, true);
			dv.NavigationItem.RightBarButtonItem = new UIBarButtonItem("Save", UIBarButtonItemStyle.Bordered, null);

		}
	}
}