Как открыть папки с treeview

 private void Form1_Load(object sender, EventArgs e)
        {
 ImageList imageList = new ImageList();         
            imageList.Images.Add(System.Drawing.Image.FromFile(@"S:\DS\Program Application\Resources\Folder.png"));
            imageList.Images.Add(System.Drawing.Image.FromFile(@"S:\DS\Program Application\Resources\File.png"));
            treeView1.ImageList = imageList;        
            ListDirectory(treeView1, "S:\\DS\\DATABASES\\ME\\Def\\");
            treeView1.ExpandAll();
         }
 private void ListDirectory(System.Windows.Forms.TreeView treeView, string path)
        {
            treeView.Nodes.Clear();
            var rootDirectoryInfo = new DirectoryInfo(path);
            treeView.Nodes.Add(CreateDirectoryNode(rootDirectoryInfo));       
        }
 
   private static TreeNode CreateDirectoryNode(DirectoryInfo directoryInfo)
        {
            var directoryNode = new TreeNode(directoryInfo.Name) { ImageIndex = 0 };
            foreach (var directory in directoryInfo.GetDirectories())
            {
                directoryNode.Nodes.Add(CreateDirectoryNode(directory));
            }
            foreach (var file in directoryInfo.GetFiles())
            {
                directoryNode.Nodes.Add(new TreeNode(file.Name) { ImageIndex = 1 , Tag = file });
            }
            return directoryNode;
        }
 
  private void treeView1_NodeMouseDoubleClick(object sender, TreeNodeMouseClickEventArgs e)
        {         
            string p = (treeView1.SelectedNode?.Tag as FileInfo)?.FullName;
            if (p != null)
            {
                System.Diagnostics.Process.Start(p);
            }
                   
        }

Path.GetDirectoryName(p);

  private void treeView1_NodeMouseDoubleClick(object sender, TreeNodeMouseClickEventArgs e)
        {
            string path = "S:\\DATABASES";
            var fullPath = Path.Combine(Directory.GetParent(path).FullName, treeView1.SelectedNode?.FullPath);
            System.Diagnostics.Process.Start(fullPath);             
        }