import DPK in d365 and add move all the objects in a single project.

paste the DPK file in the rainmain folder of rainmain drive.

then open the corext rainmain(run as administrator).

run the below syntax.

sdp apply unittesttart.dpk -a

please note - unittesttart.dpk is the name of DPK.

If you open SDB, you can see that a new change list has been created. 

then open the dev environment.

click on d365 in the tool bar.>>add ins>>create project from change list.

it will include all the objects from the single change list in one project no need to drag and drop each objects in the projects.