using System;

using System.Linq;

using System.Collections;                   

using System.Collections.Generic;       

using System.Data;

using System.Data.Linq;

using System.Data.DataSetExtensions;

using System.Xml;

using System.IO;

using System.Xml.Linq;

​

public class Program

{

    public static void Main()

    {

        string input = @"<level1><level2><level3><level4><level5><level6 leveltype=""thislevel""><level7 leveltype=""onemorelevel""><level8></level8></level7></level6></level5></level4></level3></level2></level1>";

        XElement element = XElement.Parse(input);

        var searchnode = element.Descendants("level6").Where(z => (string)z.Attribute("leveltype") == "thislevel").SingleOrDefault();

        searchnode.Parent.Dump();

​

    }

}

​

​