Manage the product categories on the function window "Data Management > Category setting"
Clicking on Expand All or Collapse All will let you see the expanded or collapsed view to the product categories.
To remove a Product Category for a specific Buyer Group; highlight the Buyer Group in the center window. At the center bottom will be a list of the selected Buy Group’s product category. Hover over the Product Category you want to remove, right click and select the remove option.
To add a Product Category to a specific Buyer Group, you shall highlight the Buyer Group in the center window. Select the Product Category you want to show the Buyer Group, drag and drop under the center bottom Product Category folder for that Buyer Group.
A Buyer Group can have more than one Product Category.
Once a product categorized under its corresponding Product Category has been ordered by a buyer(s) in a Buyer Group, the Product Category cannot be deleted from the system, but can still be removed from view from a Buyer Group.