How to make the 3 levels menu?

To make 3 levels menu the following steps:

 Step 1: Select "Settings" on the left panel.

Step 2: Click on the "Menu Order" tab.

Step 3: Turn the "Change Menu Order"  selector on. 

Step 4: Set the second and third levels of your menu by drag-drop.

The application will use the Wix pages order when the "Change Menu Order"  selector is off.
When the feature is on, the application will use its own page order.