Sorting based on a many to many relation

Lets say I have Students and Exams

query {
    studentsList {
        count
        items {
            id
            name
            exams(
                filter: { status: { equals: "COMPLETE" },
                sort: [ { completedAt: DESC } ]
             ) {
                count
                items {
                     status
                     completedAt
                }
            }
        }
    }
}

What I want to do is sort the Students by the most recent completed at. I have tried grouping, but if I group by exams using examsList, then I may not have a list of all students, but if group by Student, then I will have the same student entry.

Is there a way to do this without a custom resolver?