I can share details on how you can enter splits for a breakdown of interest in QuickBooks Online (QBO).
In QBO, if you want to split transactions from your bank into different categories. I'll be glad to show you how.
Go to the Transactions menu.
Select the Bank Transactions.
In the For Review tab, click the transaction you want to split.
Hit Split.
Select and enter all the information needed.
Then, click Apply and accept.
If you want to enter check and split interests and other information, click the +New button, select Check, and enter all the needed details. Then, to break down interests, add it to every line item of the check. Please refer to this article for guidance: Create and record checks in QuickBooks Online.
I'm leaving these articles for future reference in handling transactions and printing checks: