This option for desktop only is dialoging up a menu with all underlying levels in one overview so the frontend user can see in one overview all the levels.
The module is compatible with the template menu Color specifications.
Tthe items will be automatically divided in 5 columns and is fully compatible with the show in menu structure from you Magento backend.
The navigation is following the category tree order of your backend definition.
The navigation is also respecting your Magento tòp navigation maximum depth value set in Stores > Configuration > Catalog > Category Top Navigation
Available from version lightr 231221
Activate the mega menu option in the backend of your Magento 2 installation.
Lightr Config > Website design > Navigation
Activate the Mega menu using the switch.