How to setup a mega dropdown menu
A mega menu allows you to group submenus in columns for a more organized layout grid. Each theme has a different type of mega menu, so these images may not correspond to your theme - this is purely to explain how to set them up.
Step 1: Create the menu structure
If you haven't already, you will need to create the main navigation with nested submenus that will show in your mega dropdown. To do this go to Online Store > Navigation and edit your stores primary navigation menu.
To set up your menu like the example above, Your menu will need to span 3 levels as illustrated below:
Level 1 would contain your top-level links.
Level 2 would contain the heading for each column
Level 3 would contain the links that populate each of the above columns
Build your menu with 3 levels of menus & submenus, click save when done.
From your Shopify admin open: Online store > Themes > Customize Theme.
In the Shopify Theme Editor click on the left Sections tab and open the Header section.
At the top of this section, You will see the Add Content options where you can choose to include a Mega menu.
Once you have selected to add a Mega menu, a new block will be added to your header with some additional options:
In the field marked Menu item enter the name of the link which you would like the mega dropdown to appear from.
For example, our demo store has the following links in the main menu
Home, Shop, Blog, & Features
We wanted the mega dropdown to show under Shop, and so under Menu item, we will enter Shop exactly as it shows in our menu.
This will then set that specific link when hovered to show it's submenus within a mega menu.
Optionally you can add an image to the mega dropdown, by selecting the image in the setting Featured Image and you can link this image to a collection, page, product, etc by selecting a link in the setting Slide link.
Save your changes. If you have another menu item you want to have a dropdown below then click Add mega menu and set it up the same way.