What is the equivalent of FileBrowserDialog.SelectedPath for OFD?

Question

OFD= OpenFileDialog

I am setting up for 2 buttons for creating a ZIP file from folder and extracting a ZIP file to folder. The problem is that OpenFileDialog doesn't have SelectedPath. What should I use instead to make the second button work?

private void button1_Click(object sender, EventArgs e)
{
    FolderBrowserDialog obj = new FolderBrowserDialog(); //Mappa böngészo
    DialogResult result = obj.ShowDialog(); //Mappa kiválasztása
    if (result==DialogResult.OK && !string.IsNullOrWhiteSpace(obj.SelectedPath))
    {
        string[] folder = obj.SelectedPath.Split('\\');
        string foldertobezip = folder[folder.Length - 1];
        pathtofolder = obj.SelectedPath;
        zipfolder = string.Join(@"\", folder.Take(folder.Length - 1)) + @"\" + foldertobezip + ".zip";
        ZipFile.CreateFromDirectory(pathtofolder, zipfolder); //Elkészül a ZIP file
        MessageBox.Show("Zip file is created!");
    }
}

private void button2_Click(object sender, EventArgs e)
{
    OpenFileDialog obj = new OpenFileDialog(); //Mappa böngészo
    DialogResult result = obj.ShowDialog(); //Mappa kiválasztása
    if (result == DialogResult.OK && !string.IsNullOrWhiteSpace(obj.SelectedPath))
    {
        string[] folder = obj.SelectedPath.Split('\\');
        string foldertobezip = folder[folder.Length - 1];
        pathtofolder = obj.SelectedPath;
        zipfolder = string.Join(@"\", folder.Take(folder.Length - 1)) + @"\" + foldertobezip + ".zip";

        ZipFile.ExtractToDirectory(zipfolder, pathtofolder);
        MessageBox.Show("Folder file is created!");
    }
}