1) Go to 'Extensions' -> Choose 'Modules'

2) Next, at click 'Search Tools' -> Search by 'Type' -> Choose HikaShop Content Module

3) Click inside the title based on your category (Recommended Products, Latest Products, Best Sellers)

4) For example, click inside Recommended Products -> Go to 'Hikashop Options' tab -> Select the 'Category'

5) Once done click 'Save' button on the top

6) Before that, make sure at the product already choose the category