using System;

using System.Threading.Tasks;

using System.Threading;

using System.Linq;

using System.Collections;

using System.Collections.Generic;

using System.Reflection;

​

public class Program

{

    public static class Root

    {

        private static readonly NestedOne nestedOne;

        static Root()

        {

            nestedOne = new NestedOne();

        }

        class NestedOne

        {

            private string FindMe = "blabla";

        }

    }

​

    public static void Main()

    {   

        var nestedOne = typeof(Root).GetField("nestedOne", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);

        var fields = nestedOne.FieldType.GetFields(BindingFlags.NonPublic | BindingFlags.Instance); 

        Console.WriteLine(fields.First().Name);

    }

}