using System;

using System.Collections.Generic;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var parent = new Group("Parent");

        var child = new Group("Child");

        parent.AddChild(child);

        var json = JsonConvert.SerializeObject(parent, Formatting.Indented);

        Console.WriteLine(json);

        Console.WriteLine();

        var deserializedParent = (Group)JsonConvert.DeserializeObject(json, typeof(Group));

        Console.WriteLine(deserializedParent == deserializedParent.Children[0].Parent);

        Console.WriteLine();

        var json2 = JsonConvert.SerializeObject(deserializedParent, Formatting.Indented);

        Console.WriteLine(json2);

    }

}

​

​

[JsonObject(IsReference = true)]

class Group

{

    public string Name { get; set; }

    [JsonConstructor]

    private Group()

    {

    }

    public Group(string name)

    {

        Name = name;

        Children = new List<Group>();

    }

    public IList<Group> Children { get; set; }

    public Group Parent { get; set; }

    public void AddChild(Group child)

    {

        child.Parent = this;

        Children.Add(child);

    }

}

​