You can arrange your side menu to show a better view of category arrangement with sub-category indentaion
How to set subcategories
Navigate to Admin > Product > Category.
Click Change Sequence.
Drag and drop the category to adjust its position, then click the Save button.
You can configure up to 3 levels of depth.
The subcategories will be reflected in your storefront navigation.
How subcategories work
You can set categories up to 3 levels of depth.
When the main category is changed to `hidden`, the subcategory also becomes "hidden."
If the main category is deleted, the subcategory still exists but its depth is changed to "main."
Categories are not automatically linked to subcategory products. If you want to display all subcategory products in the main category, you must manually add the main category.