using System;

using System.Text.RegularExpressions;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var input = "RiskBrowser.[v18.1].Database.Server";

​

        var method1 = input.Split(new string[] { "[", "]","." }, StringSplitOptions.RemoveEmptyEntries);

        var method2 = System.Text.RegularExpressions.Regex.Split(input, @"(?:(?:\[([^\]]*)\])|([^\.]+))\.?",

                System.Text.RegularExpressions.RegexOptions.None).Where(m => m != string.Empty).ToArray();

        Console.WriteLine("Input: " + input);

        Console.WriteLine(string.Join("/", method1));

        Console.WriteLine(string.Join("/", method2));

    }

}