using System;

public class Program

{

    public static void Main()

    {

        var alias1 = "additionalfields.data.valueString";

        var alias2 = "additionalfields.data.valueBoolean";

        Console.WriteLine(Q(alias1));

        Console.WriteLine(Q(alias2));

    }

    public static string Q(string alias)

    {

        switch(alias)

        {

            case string stringvalue when  stringvalue.EndsWith("String"):

                return nameof(stringvalue);

            case string boolvalue when boolvalue.EndsWith("Boolean"):

                return nameof(boolvalue);

            default:

                return "";

        }

    }

}