It's nice to see you in the Community. I'd be happy to help share the steps on how to add subtotals on the invoices.
At the top right, click the Plus icon.
Select the customer's name.
Enter the information.
Highlight the last row of the group, then click Add Subtotal.
After that, the subtotal will be inserted into the next row. Also, the following article contains additional information about this, as well as a video tutorial in creating an invoice: Create an invoice in QuickBooks Online.
For additional help, feel free to reach out to our Phone Support. The phone support agents will be able to assist you in getting this resolved.
That should get you on the right track for adding subtotals on the invoices. Keep in touch if you need more help with this. I'll be happy to help you out.
Currently, we're unable to include a subtotal in QuickBooks POS. I know that this can be essential for your task and develop an easier way to group it with the corresponding percentage of the tree totals.
Though, you can enter it QuickBooks Online when creating invoices. In the meantime, I encourage you to check our Firm of the Future site to check for product updates and feature enhancements.
Additionally, you can bookmark this Community page for a reliable resource of articles about QuickBooks POS.
Keep me posted if you have other concerns with QuickBooks POS. I'm always here to help. Have a safe day ahead!