By installing this extension you can display all products from a child category in top level categories.

For example, say you have a product in category "Shoes->Red Shoes", if you were in the top level category "Shoes" you wouldn't see the product that you had allocated to the lower level category called "Red Shoes".

This extension will show all child products in the parent category.

Tested with the default Opencart theme on 2.x.x

INSTALLATION:
1. Unzip file
2. Go to Extensions->Extension Installer
3. Upload "products_show_in_parent_category.ocmod" and it should say success
4. Go to Extensions->Modifications and click the blue Refresh button on the top right
5. Module installed!

Comment if you have any questions, should work on any theme as this is a modification to the controller file only.