Hello there, @vventura.

I'm here to share some information on how you can filter all your billable expenses to specific customers in QuickBooks Online (QBO).

If the expenses assigned are Billable to your customers, we can add the Billable Expense Charge option from the Filters section to include them in the report. Follow these steps to proceed:

1. Go to report from the left menu.
2. Find and open Transaction List by Customer.
3. Click the Customize option in the upper-right corner.
4. Filter the transaction types and include Billable Expense Charge.
5. Select the specific customer you want in the Customer section. 
6. Make the necessary changes and hit Run report.
   

If the expenses aren't billable to your customers, you can run the Transaction Detail by Account report instead. This report lets you view expense transactions and the customers linked to them. Here's how:

1. Open the Transaction Detail by Account report.
2. Click the small gear icon within the report.
3. Add the Customer column. 
4. Make the necessary changes to the filters.
5. Hit Run report.
   

Moreover, check out this article to learn more about how you can focus on the details that matter the most to you when you pull up reports in QBO: Customize reports in QuickBooks Online.

I've also included this resource for your reference in case you want to export your reports to Excel: Export your reports to Excel from QuickBooks Online.

I'll be around if you have other concerns related to running reports or managing expenses. The Community and I will be around to help you. Keep safe!