using System;

using System.Xml;

public class Program

{

    public static void Main()

    {

        var xml = @"

        <test>

            <categories>

                <category>A</category>

                <category>B</category>

                <category>C</category>

            </categories>

        </test>

        ";

        var doc = new System.Xml.XmlDocument();

        doc.LoadXml(xml);

        var categories = Program.GetNode(doc);

        Console.WriteLine("--------");

        Console.WriteLine(categories);

        Console.WriteLine("--------");

    }

    public static string GetNode(System.Xml.XmlDocument doc){

        var result = "";

        var nodes = doc.SelectNodes("/test/categories/category");

        foreach(XmlNode node in nodes){

            if (result.Trim().Length != 0 ) result+=" >> ";

            result += node.InnerText;

        }

        return result;

    }

}