I appreciate you for getting back to us, hlhart.

I'll take it as you're referring to the product and services just like in the screenshot below:

The item will show as a category and sub-category when you've entered a Category on the Product/Service information page. I've added this image as a visual reference:

With that, you can either create a new item without the Category or edit the existing one and delete the Category. Here's how to modify the item:

1. From the Gear icon, select Product and services.
2. Locate the item and click Edit.
3. Delete the category on the Category field.
4. Click Save and close.

If you mean something else, please let me know. You can also add a screenshot so I can have a visual representation of your concerns.

When you're ready to link a bill from the purchase order, you can check this guide:  Add purchase orders to expenses, bills, or checks in QuickBooks Online.

I'll be around whenever you need help in creating a bill. Keep safe!