ember-drag-sort: how to determine the new parent in the dragged list?

Originally asked by @andrewsyd on GitHub.

For a nested list, is there a way to determine in the dragEnd action which "sub-list" the item has been dropped into? (e.g. a class name, id etc)

In my scenario, I am sorting ember data records that can belong to each other (i.e. a nested, 'tree' structure). When I drag one nested record "into" another (making the dragged record a child of the second record), I need to update the parent attribute in ember-data. My question is, how do you pass some id of the second record (the new parent) to the dragEnd action?

Is this even possible?