<!-- 一级栏目名称 -->
<h1>{eyou:channelartlist typeid='$eyou.field.typeid|gettoptype=###,typeid'}{eyou:field name='typename' /}{/eyou:channelartlist}</h1>
<!--二级栏目开始-->
{eyou:channel type="first" currentstyle="active"}
    {eyou:eq name='$eyou.field.grade' value='2'}
        {eyou:type typeid='$eyou.field.typeid' id='field1'}
            {eyou:eq name='$field1.parent_id' value='$field.id'}
                {eyou:assign name='$field.currentstyle' value='current' /}
                <!--current对应样式中的display:block-->
            {/eyou:eq}
        {/eyou:type}
    {/eyou:eq}
    <h2 class="{$field.currentstyle}">{$field.typename}</h2><!-- 二级栏目名称 -->
    <!--三级栏目开始-->
    {eyou:notempty name="$field.children"}
        {eyou:channel name="$field.children" id="field2"}
        <h3><a href="{$field2.typeurl}" class="{$field2.currentstyle}">{$field2.typename}{$field2.typeid}<!-- 三级栏目名称 --></a></h3>
        {/eyou:channel}
    {/eyou:notempty}
{/eyou:channel}

可以参考https://www.feikoo.com/xingyedongtai/204.html做手风琴折叠菜单