using System;

public class Program

{

    public static void Main()

    {

        var main = new Foo(){Inner = null};

        Foo selected = main?.Inner?.Inner.Inner.Inner.Inner.Inner.Inner.Inner.Inner;

        Console.WriteLine(main == null);

        Console.WriteLine(main.Inner == null);

        Console.WriteLine(selected == null);

    }

}

​

public class Foo

{

    public Foo Inner { get; set;}

}