Чтобы сделать аккордеон как вы говорите, в Конструкторе меню добавляем новое меню или редактируем старое, далее в Первом контейнере добавляем блок с меню
Дополнительно в таблице стилей CSS полностью заменяем текущие стили в строках(201-241) для меню чтобы меню действительно работало как аккордеон:
.sidebox {margin:0 0 30px;width:100%;}
.sidetitle {padding:10px 0;font-size:20px;color:#202020;text-transform:uppercase;border-top:1px solid #3a3a3a;border-bottom:1px solid #3a3a3a;font-family:'Yanone Bold';}
.sidebox .inner {padding:20px 0;}
.sidebox ul,.sidebox .catsTable {margin:0;padding:0;list-style:none;}
.sidebox .catsTable,.sidebox .catsTable * {display:block;width:auto!important;}
.sidebox li {list-style:none;padding:0;}
.sidebox li a,.sidebox .catsTable td a {display:block;color:#3a3a3a;padding:7px 10px;text-decoration:none;font-size:16px;text-transform:uppercase;position:relative;font-family:'Yanone';}
.sidebox li a:hover,.sidebox .catsTable td a:hover {color:#fff;background:#b12b43;}
.sidebox li.item-parent {position:relative;}
.sidebox li.item-parent > a {padding-right:36px;}
.sidebox li.item-parent em {position:absolute;top:4px;right:0;width:24px;height:24px;line-height:24px;font-style:normal;font-size:16px;text-align:center;z-index:10;cursor:pointer;}
.sidebox li.item-parent em.hover {color:#fff;opacity:.6;-moz-opacity:.6;filter:alpha(opacity=60);border-left:1px solid #fff;border-left:1px solid rgba(255,255,255,.6);}
.sidebox li.item-parent em:hover {color:#b12b43;opacity:1;-moz-opacity:1;filter:alpha(opacity=100);border-left:none;}
.sidebox .catNumData {display:none!important;}
.sidebox .calTable{width:100%;}
.calTable {font-size:12px;}
.calTable td {text-align:center;padding:7px 2px;}
.calTable td.calMonth {padding:0!important;position:relative;height:36px;}
.calTable td.calMonth a {color:#fff;}
.calTable td a {text-decoration:underline;}
.calTable td a:hover {text-decoration:none;}
.calMonth,.calWday,.calWdaySe,.calWdaySu {font-size:13px;color:#fff;background:#3a3a3a;}
.sidebox .calTable td.calMonth a {color:#fff;display:block;height:36px;line-height:36px;text-align:center;text-decoration:none;text-transform:uppercase;font-size:11px;font-style:italic;position:absolute;top:0;z-index:1;}
.sidebox .calTable td.calMonth a:hover {text-decoration:none;background:#b12b43;}
.sidebox .calTable td.calMonth a:first-child,.sidebox .calTable td.calMonth a:first-child + a + a {width:12%;border-left:1px solid #fff;z-index:10;}
.sidebox .calTable td.calMonth a:first-child {left:0;border-left:none;border-right:1px solid #fff;}
.sidebox .calTable td.calMonth a:first-child + a + a {right:0;}
.sidebox .calTable td.calMonth a:first-child + a {width:100%;}
.sidebox .calTable td.calMonth a:first-child + a:hover {text-decoration:underline;background:none;}
.calTable .calMday,.calTable .calMdayIs {color:#3a3a3a;background:#ebebeb;}
.calTable .calMdayA,.calTable .calMdayIsA {color:#fff;background:#b12b43;}
.calTable .calMdayIsA a {color:#f2f2f2;}
.sidebox ul ul { display:none;margin:10px 0 0 20px;padding:10px 0 0;border-top:1px solid #3a3a3a;}
.sidebox ul ul ul {margin:10px 0 0 20px;}
.sidebox iframe {border:1px solid #3a3a3a;}
.sidebox .answer {padding:5px 0 0 0;}
.sidebox input.mchat {max-width:97%;}
.sidebox textarea.mchat {max-width:92%;}
.sidebox .loginField {max-width:97%;}
.schQuery,.schBtn {display:inline;padding:0 2px;}
.sidebox ul.rate-list {margin:0;}