Hi there,
I notice you've been a member of the Community for a long time, thanks for your participation!
I want to make sure I'm on the same page as you. Which reports would you like to see the "product category"? Which part of the report would you like to see this info? In the meantime, I encourage you to check out this helpful resource from our Community:Customize Reports. The resource has more info on customizing reports in QBO. If you have further questions, don't hesitate to ask. I'm here to assist. :)