How do use hook_views_pre_render() to modify view fields
Found the answer:

// https://drupal.stackexchange.com/questions/272495/how-to-get-views-field-names-values-for-hook-views-pre-render
foreach ($view-&gt;result as $key =&gt; $value) {
  //- Get parent_id value 
  $parent_id_value =  $value-&gt;_entity-&gt;parent_id-&gt;getValue()[0]['value'];
  //- Get parent_type value
  $parent_type_value =  $value-&gt;_entity-&gt;parent_type-&gt;getValue()[0]['value'];
  drupal_set_message($parent_id_value .' | '.$parent_type_value);
}