Are you asking if there is an assignment that can be created as a single assignment, but then be graded and scored in groups? For example, there is a group book report with members of the class split in to groups of 4. Would you be able to create 1 book report assignment in the system, but then just grade the group and have the grade go to the members of the group instead of having to assign each grade individually to each student.
Right now, there wouldn't be a way to that, but I think that would make a great Enhancement Request.
Let me know if that doesn't encapsulate what you are looking for.