Hi there, @useraccounts5.

For you to link a product to multiple purchase products, you can use a Bundle item. It is a combination of multiple or Group items you often sell together into Bundles so you can easily add multiple items to transactions. 

Here's how to create a bundle item:

1. Go to the Sales menu. Then, select the Products and Services tab.
2. Click the New button and choose Bundle.
3. Check the box for Display bundle components when printing or sending transactions and add the product or services in the line items.
4. Once completed, click Save and close.

I added a screenshot for visual reference.

Here's an article you can read to learn more about bundles: Change Product and Service Types.

You can also use this article as a future reference if you want to apply a bundle item in the invoice: Add bundle item to invoice.

Please know that I'm always here to help, so don't hesitate to reach out anytime. Have a nice day!