Putting a list of objects into an object

I am having an issue with the following structure:  {                                                -----→  parentObject    “Items” : [                               ---------→   lineItems           {                                           -----------> innerObject                  “name”: “bob”            }     ] } I’m able to RETRIEVE the lineItems and then use another Retrieve to get the list of inner objects. However, when I want to create this structure I’m unable to do the reverse process. If anyone can help that would be greatly appreciated. Again, I can successfully get the list of objects out of the object. However, putting a list into the same object structure is not working.   I have a microflow that requires the above structure. However, I need to make the structure from scratch within mendix. This involves creating a list which we have done successfully. The next step would be creating the parent  lineItem object and setting its member to the value to the newly created list, however that list doesn’t appear in the dropdown. Hopefully this makes sense.  
1 answers

A bit of pseudo modelling here, but assume the following domain model based on the provided json structure:

In a microflow:

Action 1 is the retrieve of the list of innerobjects

Action 2 creates an object of type lineitems and the list of innerobjects is associated like below:

Action 3 creates an object of type parentObject and the newLineItems object is associated like below:

I think you need to change the domain model to allow for this, but I hope this points you in the right direction.