I know a way on how you can pull up the item details when running a purchasing report in QuickBooks Online, bbradley.

You can group the Open Purchase Orders Detail report by Vendor to pull up each item detail from the purchase orders.

In case you need help customizing your QuickBooks reports, you can visit this article: Customise reports in QuickBooks Online. You can also memorize it to save its current customization settings. It serves as your record and helps you quickly access it for future use. 

You're always welcome to post any concerns you have in this space. I'll be here if you need assistance with QuickBooks or have follow-up questions about the purchase order report. Have a great day!