now there is an array of multi-level dots, and you want to reorganize the array according to the dot level level field in this array, with the goal of reassembling a composite array.
the original array code is as follows:

list: [
            {
                "id": 30064771072,
                "lastModified": "2019-02-13 20:14:42:000",
                "userCount": 4,
                "deviceCount": 4,
                "level": 0,
                "name": "11"
            },
            {
                "id": 30081548288,
                "lastModified": "2019-01-30 14:36:33:729",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": ""
            },
            {
                "id": 30081679360,
                "lastModified": "2019-01-30 14:23:33:345",
                "userCount": 0,
                "deviceCount": 0,
                "level": 2,
                "name": "120"
            },
            {
                "id": 30081744896,
                "lastModified": "2019-01-30 06:52:07:915",
                "userCount": 0,
                "deviceCount": 0,
                "level": 2,
                "name": "360"
            },
            {
                "id": 30098325504,
                "lastModified": "2019-01-29 09:52:27:640",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": "120"
            },
            {
                "id": 30131879936,
                "lastModified": "2019-01-29 10:14:03:897",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": ""
            },
            {
                "id": 30148657152,
                "lastModified": "2019-01-30 02:44:48:868",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": ""
            },
            {
                "id": 30165434368,
                "lastModified": "2019-01-30 14:39:28:452",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": ""
            },
            {
                "id": 30182211584,
                "lastModified": "2019-01-30 15:32:40:672",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": ""
            },
            {
                "id": 30215766016,
                "lastModified": "2019-01-30 15:33:17:230",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": ""
            },
            {
                "id": 30232543232,
                "lastModified": "2019-01-30 07:35:41:689",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": "77"
            },
            {
                "id": 30249320448,
                "lastModified": "2019-01-30 08:30:30:981",
                "userCount": 0,
                "deviceCount": 0,
                "level": 1,
                "name": "33344"
            },

        ],

level is a site rating field, which has four levels: 0meme, 1meme, 2pje 3. The target array is based on this rating
the target array code is as follows:

listBox:[{//
            id:"",
            name:"",
            lastModified:"",
            userCount:"",
            deviceCount:"",

            children:[{ //
                    id:"",
                    name:"",
                    lastModified:"",
                    userCount:"",
                    deviceCount:"",

                    maxList:[ {//
                        id:"",
                        name:"",
                        lastModified:"",
                        userCount:"",
                        deviceCount:"",   

                        minList:[]//
                        
                    }]                   
            }]
        }],  

I originally intended to use the for loop to nest the if implementation, but the implementation was modified several times
and the final implementation code is as follows:

 for(let i=0;i<this.list.length;iPP){//
                if(this.list[i].level==0){//1
                        this.listBox[i].children = "";
                    }else if(this.list[i].level==1){//2
                        this.listBox[i].children[i].maxList = this.list[i];
                        this.listBox[i].children[i].mediumList = "",
                        this.listBox[i].children[i].minList = ""
                    }else if(this.list[i].level==2){//3
                        this.listBox[i].children[i].mediumList =this.list[i];
                        this.listBox[i].children[i].minList = ""
                    }else {//4
                        this.listBox[i].children[i].minList = this.list[i];
                    }
                    this.listBox[i].id = this.list[i].id;
                    this.listBox[i].name = this.list[i].name;
                    this.listBox[i].lastModified = this.list[i].lastModified;
                    this.listBox[i].userCount = this.list[i].userCount;
                    this.listBox[i].deviceCount = this.list[i].deviceCount;
               
            }
            console.log(this.listBox);

however, my method gets cold when it doesn"t get to console.log. And my method is not efficient, each time the page is loaded, I have to traverse all the data in the for loop. I hope all the great gods can teach us an efficient and feasible method. Thank you very much!