Creating a list of parts with quanites in data type

I found this posting.

This is more of what I’m wanting to do.

My ‘Assembly’ data type is this:

assembly data type

And now I have an ‘Assembly Line Item’ data type:

assembly line item data type

So to create an assembly I’m using this popup:

assembly popup

When clicking the ‘ADD’ button I want to add the selected material and quantity to the repeating group. But I’m planning on using a Custom State to add the inputs to and then create the things when the ‘Add Assembly’ button.

I’m wanting to create a custom state of ‘Assembly Line Item’ then when I create the assembly create all the ‘Assembly Line Item’ data types. If that makes sense.

Maybe my problem is I’m thinking about how I would do this with a programming language and not how to do this with Bubble.

Appreciate any advice.