folders.gs

    var folders = DriveApp.getFoldersByName("Università");
    var subfolder = null;
    if (folders.hasNext()) {
      var folder = folders.next();
      var subfolders = folder.getFoldersByName("Sbobine");
      if (subfolders.hasNext()) {
			var folder = subfolders.next();
			var subsubfolders = folder.getFoldersByName("5o Anno");
			if (subsubfolders.hasNext()) {
				var folder = subsubfolders.next();
   				var materiafolder = folder.getFoldersByName(form.materia);
   				subfolder = materiafolder.hasNext() ? materiafolder.next() : folder.createFolder(form.materia);
    	}
    }
}