Hello, simplifaster.

Filtering fields with empty information is possible in QuickBooks Online. The thing is, the report won’t be able to show data if the filtered field has no information. 
Also, these are the only fields that are available to filter:

• Terms
• Account
• Transaction Type
• Customer
• Created Date
• Due Date
• Memo
• Number
• Amount

For now, you can follow the steps provided by my colleague to filter empty tracking number. I’ll also make sure to take note of this option and share it to our developers for future updates. 

Please visit us again if you have other questions about QuickBooks.