Hi pmh5,

I see how important it is for you to be able to produce a budget report grouped by classes. While this isn't a feature in QBO, you can export your budget report to Excel and manually arrange the data to get a budget per account per month for each class.

I also encourage you to submit feedback about this so our product development team can create enhancements in future updates. 

You can always visit us back in this thread if you have any other questions. Take care and have a good one.