Good day, @lisa20.
Thank you for choosing QuickBooks as your accounting partner. I can share some insights about the bundle feature in QuickBooks Online.
A bundle is a collection of products and services you sell together. There is no specific field for the Quantity on Hand for a bundle.
If you'd like to increase or reduce its number, you have to create an inventory adjustment per item. If you also create a sales transaction with the bundle, automatically the Quantity on hand of the items will decrease.
For in-depth information, please refer to these articles:
That should do it. Let me know if there's anything else you need or you have follow-up question about inventory. I'm still here to help you more.