If the platform did not automatically detect the correct navigation, you can select new navigation from your desktop site from within the editor.
1. From within the design section of the editor click on layout and then the customize button under the navigation style section.
2. Click on the Settings tab and then link that says Select From Your Site.
3. A panel will open, showing your desktop site, from there you can select the correct navigation.
4. You can use the expand and contract buttons to change the size of the selected area