Hello and good day too, @tmogodi,
At the moment, we're unable to run a Trial Balance by Class Report in QuickBooks Online. Having the option to customize filters for an existing Trial Balance is a good idea.
As a workaround, you can run the Balance Sheet by Class (less Net Income line) and Profit and Loss by Class reports. Once done, export it to Excel and merge them together.
The combined adjusted numbers distributed by class should be the same as the numbers in Trial Balance by Class if available.
To transfer a report to a worksheet, click on the Export icon on the report, then choose Export to Excel. See this screenshot:
I'll be adding some related links to help you get your way around the Reports feature in QBO:
I appreciate your time today. If you have any questions about QuickBooks reports, let me know in the comment below. I'll be right here if you need anything. Have a nice day!