One of the biggest updates to the new theme, is the creation of a Navigation Builder. This was created to streamline the process to maintain and update site navigation using the Cascade CMS interface. This allows site editors the ability to customize navigation without needing to touch HTML code.
There are one level of drop down menu hierarchy available
Keep in mind external links must be created before adding them to the Navigation builder
Instructions
Select _Navigation Builder block.
Click Edit.
Build your Navigation and select Preview Draft.
Click Submit.
Notes:
Use the + to create a new navigation items
Use the x to delete a navigation item
Use the Up arrow and Down Arrows to organize your navigation
Select the "sub-hierarchy" type to create a drop down menu,
Don't forget to provide a heading for your drop down menu.