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);
        }
    });
});