If you want to limit the number of individual products added in the bundle which max of one or more than one product each, you need to follow these steps:
Go to Bundle settings.
Enable Quantity Validation.
Enable the toggle for quantity validation.
Enter the desired maximum number of products to be added at the product level.
This limit will be applied to each and every individual product added in the bundle.
Navigate to the Bundle settings as shown in the image below and then enable the quantity validation toggle.
If you are facing any troubles or have further customization requests,