Hello,
To manage this you have to first create main categories and in their own subcategories, here on Components => HikaShop => Categories.
Later in all your products configuration just set the required sub-category (or maybe several) in Components => HikaShop => Products.
Last step, configure your categories listing Menu item, here in Menus => Menu item and look for (default) Categories listing.
in configuration page have a look on Categories Options tab, and look for Data display part and change Sub elements filter option for Grouped by category.
Hope this will help.
Regards,