The idea behind this process, is that we want to have an order Nintex form that has a repeating section with order items in it. Those order items, we want to appear in another list. An Order Items list. There are a few caveats here. We want to make sure that if you go back to the original order, maybe it's in the middle of an approval process, and you make changes to those order items, or add new ones, that the Order Items list is updated accordingly.
The other thing, is if someone goes into the Order Items list and makes a change to an order, the original request form should be updated.
This process is built out in 3 workflows. It could probably be done in 2, but I like separating the New item and Modified item workflows, unless there is a lot of cross over in logic.
The downloads below contain all the files for you to reproduce the scenario that is shown in the video above. I'd recommend you upload the list templates to your site, the create the lists in this order:
Then open up Nintex Forms on the Order list and import the form. Open Nintex Forms for the "Order Items" list and import that form. You'll then be able to import the workflows and publish them, and run them.
There's no reason why the items needs to go to another SharePoint list. It could create items in a SQL table, Oracle Table, Dynamics CRM, Salesforce, etc.