Running a report with detailed subsection is currently unavailable in QuickBooks Online. As a workaround, you run the Transactions Detail by Account or Account List report and customize it to show all the information you need.
To learn more about customizing QuickBooks reports, see the articles below:
QuickBooks Online uses a concept called 'Source' and 'Targets' to build transactions and reports. Understanding this concept will help you create more effective reports. The following article will help give more details about this: Targets vs. Sources overview.
I'd be happy to help if you need additional assistance. Have a good one.