I understand the importance of finding the customer's invoice linked to a bill. I want QuickBooks Desktop to have this feature as much as you do. However, this feature is not available in QuickBooks Desktop. With this, I strongly urge you to share your thoughts with our software engineers. They carefully examine customer feedback, especially when determining how to improve QuickBooks.

Here's how:

1. Go to the Help menu at the top.
2. Select Send Feedback Online.
3. Click Product Suggestion.
4. Click on the drop-down for Type of Feedback and select Product Suggestion.
5. Select the Product Area.
6. Enter your thoughts and suggestions.
7. Click Send Feedback.

In the meantime, I suggest running a Transaction List by Customers report and looking for split invoice transactions. From there, check the amount of your bill and compare it to the split invoices found in the report. That will help you find the linked invoice to a bill.

Moreover, I'm adding this article as your reference in customizing your reports in QBDT: Customize reports in QuickBooks Desktop.

I hope this post finds you well and keep us posted if you have any inquiries about managing your QuickBooks account. We'll be here to provide you guidance 24/7 and ensure you have the best experience with QuickBooks.