using System;

public class Program

{

    public static void Main()

    {

        Class1 c1 = new Class1();

        bool res = c1?.innerClass?.val1 != null;

        Console.WriteLine(res);

​

    }

}

​

public class Class1{

    public Class2 innerClass { get; set; }

}

​

public class Class2{

    public string val1 {get; set;}

}