private FolderBrowserDialog folderBrowserDialog = new FolderBrowserDialog();

        public Form1()
        {
            InitializeComponent();
        }

        string[] slupyPath;

        private void button1_Click(object sender, EventArgs e)
        {
            DialogResult result = folderBrowserDialog.ShowDialog();
            if (result == DialogResult.OK)
            {
                string folderName = folderBrowserDialog.SelectedPath;
                string[] slupy = Directory.GetDirectories(folderName);
                slupyPath = slupy.Select(y => Path.GetFileName(y)).ToArray();

                ListViewItem[] x = new ListViewItem[slupyPath.Length];
                for(int i = 0; i < slupyPath.Length; i++)
                {
                    x[i] = new ListViewItem(slupyPath[i]);
                }
                listViewPoles.Items.AddRange(x);
            }
        }