基于layui如何实现无限极联选择器（附代码）

<div class="layui-form-item">
 <label class="layui-form-label">选择框</label>
 <div class="layui-input-block">
 <input type="text" id="a" class="layui-input" readonly="readonly">
 </div>
</div>

layui.use(['form',"jquery","cascader"], function(){
 var $ = layui.jquery;
 var cascader = layui.cascader;
 
 var data = [
 {
 value: 'A',
 label: 'a',
 children: [
 {
 value: 'AA1',
 label: 'aa1',
 },
 {
 value: 'BB1',
 label: 'bb1'
 }
 ]
 },
 {
 value: 'B',
 label: 'b',
 }
 ]
 cascader({
 elem: "#a",
 data: data,
 // url: "/aa",
 // type: "post",
 // triggerType: "change",
 // showLastLevels: true,
 // where: {
 // a: "aaa"
 // },
 value: ["A", "AA1"],
 success: function (data) {
 console.log(data);
 }
 });
});