using System;

using System.Collections.Generic;

using System.Text.Json;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var json =

"""

{

   "result":[

      [

         {

            "id":"001",

            "name":"test01"

         },

         {

            "id":"002",

            "name":"test02"

         },

         {

            "id":"003",

            "name":"test03"

         }

      ]

   ]

}

""";

        var root = JsonSerializer.Deserialize<Root>(json);

        var item = root.result[0].First(o => o.id == "002");

        Console.WriteLine(item.name);

    }

}

​

public class Item

{

    public string id { get; set; }

    public string name { get; set; }

}

​

public class Root

{

    public List<List<Item>> result { get; set; }

}