Products in my subcategory do not show on the main category page. How do I fix it?

A category page lists only products assigned to that exact category. Products assigned only to Shirts do not appear on Clothing; instead, Clothing shows Shirts and Trousers as subcategory links and in its Filter By Category option.

To show them on the main category page as well:

1. Open each product under Products → Products.
2. In the Organization card, select both the subcategory and the parent category under Categories.
3. Click Save.

Shoppers can then browse everything under Clothing and narrow it down with the subcategory filter.