Hi LisaW62,
It's nice to see you in Community. Welcome! QuickBooks Online class tracking feature is a great way to get a clear picture of transactions by departments and other segments of your business. I'll be happy to provide more information so you're on the right track with your QuickBooks goals!
Currently there isn't a way to allocate transactions to several classes by a percentage. However, if you'd like to see this in a future update, you can submit a suggestion to our Development Team. Your recommendations are greatly appreciated and assist with improving your overall customer experience with QuickBooks Online.
If you have any other questions, feel free to reach back out. We'd be glad to help!