gistfile1.txt

        private readonly List<FolderVm> _folders = new List<FolderVm>();
        
        public void UpdateFolders(string path)
        {
            var directoryInfo = new DirectoryInfo(Path.GetDirectoryName(path));

            var iteratedDirectories = new Stack<DirectoryInfo>();

            iteratedDirectories.Push(directoryInfo);

            while (directoryInfo != null)
            {
                directoryInfo = Directory.GetParent(directoryInfo.FullName);

                if (directoryInfo != null)
                    iteratedDirectories.Push(directoryInfo);
            }
            
            while (iteratedDirectories.Any())
            {
                var iteratedDirectory = iteratedDirectories.Pop();

                var parentDirectory = Directory.GetParent(iteratedDirectory.FullName);

                if (parentDirectory == null && _folders.All(x => x.Path != iteratedDirectory.FullName))
                {
                    _folders.Add(new FolderVm(iteratedDirectory.FullName));
                }
                else if (parentDirectory != null)
                {
                    var parentDirectoryVm = GetParentDirectoryVm(_folders, parentDirectory.FullName);

                    if (parentDirectoryVm.Folders.All(x => x.Path != iteratedDirectory.FullName))
                    {
                        parentDirectoryVm.Folders.Add(new FolderVm(iteratedDirectory.FullName));
                    }
                }
            }
        }
        
        private FolderVm GetParentDirectoryVm(IReadOnlyCollection<FolderVm> directories, string path)
        {
            var parentDirectoryVm = directories.SingleOrDefault(x => x.Path == path);

            if (parentDirectoryVm != null)
                return parentDirectoryVm;

            foreach (var directory in directories)
            {
                parentDirectoryVm = GetParentDirectoryVm(directory.Folders, path);

                if (parentDirectoryVm != null)
                    break;
            }

            return parentDirectoryVm;
        }