PathTreeList

using System;
using Sitecore.Data.Items;
using Sitecore.Shell.Applications.ContentEditor;

namespace Custom.Common.Fields
{
    /// <summary>
    /// The custom tree list.
    /// </summary>
    public class PathTreeList : TreeList
    {
        /// <summary>
        /// Gets the header value with the path.
        /// </summary>
        /// <param name="item">The item.</param>
        /// <returns>
        /// Header text for list item.
        /// </returns>
        protected override string GetHeaderValue(Item item)
        {
            if (item == null)
            {
                return base.GetHeaderValue(null);
            }
            
            var result = item.DisplayName;
            var nextItem = item.Parent;
            while (nextItem != null && !nextItem.TemplateName.Equals("HomeTemplateName", StringComparison.InvariantCultureIgnoreCase))
            {
                result = $"{nextItem.DisplayName}/{result}";
                nextItem = nextItem.Parent;
            }

            return result;
        }
    }
}