<ul>
<{foreach from=$category item=cat name=cat}>
<li>
<a href="<{$cat.link_url}>"><{$cat.name}></a>
<{foreach from=$subcategory[$cat.bid] item=scat name=scat}>
<{if $smarty.foreach.scat.first}><ul><{/if}>
<li>
<a href="<{$scat.link_url}>"><{$scat.name}></a>
</li>
<{if $smarty.foreach.scat.last}></ul><{/if}>
<{/foreach}>
</li>
<{/foreach}>
</ul>