Not quite sure what are you trying to achieve. To print only some members try doing this:
foreach ($your_array as $key => $value) {
echo '<pre>';
echo $value->person_id . " ";
echo $value->person_name . " ";
echo $value->role_title . " ";
echo "\n";
echo '</pre>';
}
And if you can print it, you can save it to new array however you desire.