coba lakukan ini,
$offenses = \App\LawCase::raw(function ($collection) {
return $collection->aggregate([
[
'$match' => ['active' => true, 'type' => 'criminal', 'current_offense_literal'=> ['$exists' => true]]
],
[
'$group' => ['_id' => '$current_offense_category', 'offense_literals' => ['$addToSet' => ['current_offense_literal'=>'$current_offense_literal', 'current_offense_literal_value' =>'$current_offense_literal_value']]]
]
]);
});