using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Xml;

using System.Xml.Linq;

​

​

public class Program

{

public static void Main(string[] args)

    {

        var xml = @"<Employee>

    <Entity>

        <Id>1</Id>

    </Entity>

</Employee>";

​

        var doc = XDocument.Parse(xml);

        var id = doc.Descendants("Id").Single(e => e.Value == "1");

        var path = string.Join("/", id.AncestorsAndSelf().Select(e => e.Name.LocalName).Reverse());

​

        Console.WriteLine(path);

​

        using (var reader = XmlReader.Create(new StringReader(xml)))

        {

            var elements = new Stack<string>();

​

            while (reader.Read())

            {

                switch (reader.NodeType)

                {

                    case XmlNodeType.Element:

                        elements.Push(reader.LocalName);

                        break;

                    case XmlNodeType.EndElement:

                        elements.Pop();

                        break;

                    case XmlNodeType.Text:

                        path = string.Join("/", elements.Reverse());

                        break;

                }

            }

        }

​

        Console.WriteLine(path);

    }

}