Hello there, shastaktn.

Yes, there is. You can follow the steps below to export your assemblies in QuickBooks Desktop. 

1. From the File menu, select Utilities.
2. Choose Export and select Lists to IIF Files.
3. Click Item List. Then, OK.

It'll then create an IIF file that has your entire item lists with your assemblies. For additional details when exporting them, you can check this link. 

When creating a new item or build assembly, this is how it looks like:

Also, I'd recommend checking the articles below. Each of them talks about using assemblies and sub-assemblies within your company file:

• Track the products you manufacture.
• Combine your inventory items to build finished goods. 

Visit again if you have additional questions. I'm right here to assist you anytime. Stay safe and have a good one!