elementui 树控件默认隐藏第三级菜单

<!-- 必须属性：  default-expanded-keys  node-key 
default-expanded-keys 设置默认展开的数组
-->
<el-tree :default-expanded-keys='idArr' node-key="id" :data="orgtree" :props="defaultProps" @node-click="handleNodeClick" highlight-current ></el-tree>

data() {
    return {
      defaultProps: {
        children: "children",
        label: this.labelFn
      },
      orgtree: [],
      idArr:[]
    };
methods:{
getOrgTree() {
      get("地址").then(res => {
        this.orgtree = res.data.data;
     //将第一级的id push进数组
        this.orgtree.forEach(item=>{
            this.idArr.push(item.id)
        })
    //将第二级的id push进数组
        if(this.orgtree[0].children.length>0){
          this.orgtree[0].children.forEach(item=>{
            this.idArr.push(item.id)
        })
        }
      });
    },
}