Looking at best practice for how to construct and maintain many through many relationships

Why wouldn't result table contain both user_id and test_id? It would been easier then, right ?

Oh yeah never thought of that? So then would I be able to just call Groups hasmany results through Students?

wait hangon the Student_UPN is the student_id... just named according to local nomenclature

Yep :)

I think the issue is that group is many to many to student but I don't know how to call group has many results through pivot with students

Like this maybe:

User::whereHas('group', function($query) use ($groupId) {
$query->where('id', $groupId);
});

Here is the docs https://laravel.com/docs/5.5/eloquent-relationships#querying-relationship-existence

Or you can use $groupName instead of the $groupId

but it is setup like this;

groups-(hasmany)<group_student>(hasmany)-students-(hasmany)<_results>(belongstomany)-tests

So just querying the existence is not going to help because there will always be students with a group because they will always be in multiple groups.

if you pass parameter to whereHas() like I did above your not only querying existence but existence of relation with additional query that you've passed so i would get results like this:

Result::whereHas('students', function($query) use ($groupId) {
    $query->join('group_student', 'group_student.student_id', '=', 'students.id')
             ->where('group_student.group_id', $groupId);
}):

I think that you can't use whereHas() in callback of whereHas(), so i used join for second relation....

been tinkering with what you gave me and I've come up with:

  $response = Student::whereHas('groups', function ($query) use ($group_id){
      $query->where('group_id', $group_id);
    })->leftjoin('results', function ($join) use ($test_id) {
      $join->on('students.id', '=', 'results.student_id')
           ->where('test_id', $test_id);
    })->orderBy('last_name', 'asc')->get();

Only issue is that the students.id is overwritten by results.student_id, this can't happen because when sending the corrected results back to the database I'll need to rely on both student.id for some things and result.id for others...

any ideas?