Hello, Larry.
I understand that this will take a lot of your time and effort, as well as for your business. Please view the suggested solution from one of our experts regarding a similar question you've asked in this thread: Convert sub-customers With children into projects.
You can check this article to understand how your features and data transition from QuickBooks Desktop to QuickBooks Online: Learn how features and data move from QuickBooks Desktop to QuickBooks Online.
Feel free to reach out if you need further assistance or have any inquiries about managing jobs and projects in QuickBooks Online.
