You can use the [Menu block][1] module, or print sub-menus or any level menus.

    echo theme('links__system_main_menu', array(
      'links' => menu_navigation_links('main-menu', '1'),
      'attributes' => array(
      'id' => 'main-menu-level-2-id',
      'class' => array('links')
    )));






  [1]: https://drupal.org/project/menu_block