嵌套折叠怎么实现

<div id="content2" class="mui-control-content">  
            <ul class="mui-table-view mui-table-view-chevron">  
                <li class="mui-table-view-cell mui-collapse"><a class="mui-navigate-right">产品</a>  
                    <ul class="mui-table-view mui-table-view-chevron">  
                        <li class="mui-table-view-cell"><a class="mui-navigate-right">iOS</a>  
                            <ul class="mui-table-view mui-table-view-chevron">  
                                <li class="mui-table-view-cell"><a class="mui-navigate-right">PC方案</a>  
                                </li>  
                                <li class="mui-table-view-cell"><a class="mui-navigate-right" >手机方案</a>  
                                </li>  
                                <li class="mui-table-view-cell"><a class="mui-navigate-right">TV方案</a>  
                                </li>  
                            </ul>  

                        </li>

我也想求，说的是目前mui只支持单层折叠栏