1. Select the section and click on update button
2 Click on Categories (in the left ) of the Update section page.
3. Click on Assign Categories button that appears on Update Section: Categories
Please note that Category assignment is used during product auto-placement only for leaf sections.
Please refer to the section Using Product Autoplacement in the page
After you have created the desired mappings between your leaf sections and Oracle Inventory categories, you must run the iStore Product Autoplacement Concurrent Program to populate the sections with products. You also can instruct the concurrent program to run in Replace mode, and it will update existing products as well as remove products which no longer match the category-section mappings.
Please refer to the link I provided in the previous link. It has all the details in it...