HI Vichitra Choudhary,
1. Place the parent data view(Dataview1) first and the place the 2 data view inside the Data View1 and select the Datasource as Association and select the Association which you have created, In similar fashion you can have multiple DataViews in a single page.
The only change that you have to do is place data views in their Parent Data Views.
2. The fields are not editable because you have created association in the domain model but you have set the association while creating the objects. You can call a call Microflow and create necessary entities and set the associations and call the page.
Inside the page you can design the dataview in nested fashion.
For your Reference :
Context for Second Dataview :
You can build nested Dataview in a similar fashion.
Hope this helps !!
Please see this screenshot for above comment