The Pages Widget can be added to a Mega Menu to create a new one. This can be done to expand your current mega menu or replace one if it was deleted. The list of links is automatically generated based on the site map.
Instructions
Hover your cursor over the appropriate Mega Menu tab

Click the Pin button

Click the Widgets tab

Drag and drop the Pages widget into the Mega Menu

Select the appropriate Skin to match the existing Mega Menus

Click Save

This widget automatically populates a clickable list of the subpages of the current page into the content area. If there are no subpages, sibling pages will be displayed. This is also known as a Dynamic Subpage. See more on the Pages Widget and other Content Widgets
A presentation option for menus in the global/main navigation that displays the menu in a large box that may span the width of the site automatically populates, and contains the subpages for each section. Mega menus can also contain widgets, buttons, or other graphic items