1차 메뉴만 있을때랑 2차메뉴가 있을때 class 명을 다르게 하고 싶습니다.

<ul>
<li loop="$GNB->list => $key1, $val1" class="active_2"|cond="$val1['list']" class="active"|cond="!$val1['list']">
<a href="{$val1['href']}" target="_blank"|cond="$val1['open_window'] == 'Y'">{$val1['link']}</a>
<block cond="$val1['selected']">{@ $_selected_menu = $val1}</block>
<ul cond="$val1['list']" class="depth2">
<li loop="$val1['list'] => $key2, $val2" class="more"|cond="$val2['list']">
<a href="{$val2['href']}" target="_blank"|cond="$val2['open_window'] == 'Y'">{$val2['link']}</a>
<ul cond="$val2['list']" class="depth3">
<li loop="$val2['list'] => $key3, $val3">
<a href="{$val3['href']}" target="_blank"|cond="$val3['open_window'] == 'Y'">{$val3['link']}</a>
</li>
</ul>
</li>
</ul>
</li>
</ul>

이런 배열이면 될겁니다. 첫번째 li구문만 보세요.