Wix Stores: Displaying Product Categories on Mobile
If you display the category page on your site, customers can use it to navigate through your live categories. However, it's important to remember that the category list is not visible on mobile devices. If you want customers on mobile to have access to your subcategories, add them to the site menu.   You decide whether you want to add them only on the mobile version of your site or both on desktop and mobile. Adding categories only to your mobile site menuIf you prefer not to add your product categories to the desktop version of your site menu, you can still add them to mobile. This way, customers visiting your site using a mobile device can easily find the types of products they're looking for. Wix EditorStudio Editor
Click the Switch to Mobile icon at the top of your editor.
Click the site menu. Click the Settings icon . Click Set as Advanced. Click Set as Advanced to confirm. Click the menu in your editor. If not already open, click Manage Menu. Click + Add Menu Item at the bottom. Select Link. Select Page on the left. Select Category Page from the Which Page? drop-down. Select the category you want to display from the Which item? drop-down. Click Done. (Optional) Rename the category. (Optional) Drag categories to make them into subcategories.In the Studio Editor, you have the option of creating specific menus and only showing them on the mobile breakpoint.  Learn more about hiding and unhiding elements.
Go to the mobile breakpoint.  Add a new menu element:
    
Click Add Elements  on the left side of the editor. Click Menu & Search.  Drag the relevant menu design onto the page.   Create a new custom menu showing the product categories:
    
Click Manage Menu. Click the drop-down under Which menu is displayed? and select Manage Site Menus. Click + Add New Menu at the bottom. Enter a name for the new menu.
Note: This name isn't visible to visitors.   (In the Manage Menu panel) Add the product categories to the new menu: 
    
Click + Add Item at the bottom. Select Link. Select Page on the left. Select Category Page from the Which Page? drop-down. Select the category you want to display from the Which item? drop-down. Click Done.   Hide the menu from the other breakpoints:
    
Go to the tablet and desktop breakpoints. Right-click the menu element and select Hide.   Adding categories to desktop & mobile site menusBy default, the category page is added to the site menu with the name "Shop". This link directs customers to the "All Products" category. You can add direct links to each of your other categories (e.g. Body, Nutrition).If your site has a lot of products and categories, you can add subcategories to the site menu.Wix EditorStudio Editor
Click Pages and Menuon the left side of the editor. Click Site Menu. Click +Add Menu Item at the bottom. Select Link.
Select Page on the left. Select Category Page from the Which Page? drop-down.
Select the category you want to display from the Which item? drop-down. Click Done. (Optional) Rename the category and click Done. (Optional) Make the category you added into a subcategory:
    
Click Pages and Menuon the left side of the Editor. Click Site Menu. Drag the relevant menu items under and to the right of the relevant category.  
Select the relevant menu in your editor. Click Manage Menu. Click +Add Item. Select Link. Select Page on the left. Select Category Page from the Which Page? drop-down. Select the category you want to display from the Which item? drop-down. Click Done.
(Optional) Rename the category. (Optional) Drag categories to make them into subcategories.