{foreach $menus as $one}{notempty name='one.sub'}

{foreach $one.sub as $two}{empty name='two.sub'}
• {$two.title|default=''}
{else}
• {$two.title|default=''}

  {foreach $two.sub as $thr}

  {$thr.title|default=''}

  {/foreach}

{/empty}{/foreach}

{/notempty}{/foreach}