modules/locale/views_handler_field_locale_group.inc

<?php

class views_handler_field_locale_group extends views_handler_field {
  function render($values) {
    $groups = module_invoke_all('locale', 'groups');
    // Sort the list.
    asort($groups);
    $value = $this->get_value($values);
    return isset($groups[$value]) ? $groups[$value] : '';
  }
}