Convert Flat string list to hierarchical object using C#

hierarchicalConverter

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            var forumLib = new List<string> 
            { 
               "Offices_Pune", 
               "Offices_Pune_HR", 
               "Offices_Pune_PMO", 
               "Offices_London", 
               "Offices_London_DEV", 
               "Offices_London_DEV_DOTNET", 
               "Offices_London_DEV_JAVA", 
               "Offices_London_QA", 
               "Offices_Mumbai", 
               "Finances", 
               "Sales", 
               "HR", 
               "Sales_Training" 
            };

            Node n = new Node();

            foreach (var nodepath in forumLib)
            {
                n.AddPath(nodepath);
            }

        }

        public static void AddPath(this Node sourceNode, string path)
        {
            char[] charSeparators = new char[] { '_' };
            string[] parts = path.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries);
            Node current = sourceNode;

            foreach (string part in parts)
            {

                Node child;

                if (!current._nodes.TryGetValue(part, out child))
                {

                    child = new Node
                    {
                        Path = part
                    };


                    current._nodes[part] = child;
                }
                current = child;
            }
        }



    }
    public class Node
    {
        public readonly IDictionary<string, Node> _nodes =
            new Dictionary<string, Node>();

        public string Path { get; set; }
    }
}