Get the first instance of a field where it's not null from rows
Solved it, makes sense now!

public function get_first_instance($field, $rows) {

  foreach($rows[0]['#rows'] as $row) {
    $entity = $row['#row']-&gt;_entity;

    if($entity-&gt;hasField($field)) {
      $value = $entity-&gt;get($field)-&gt;getValue();

      if(! empty($value)) {
        return $value;
      }
    }
  }

  return dump('Field not found: '.$field);
}