code: void showParentFolder() {
  
          CmsUUID parentId = (CmsUUID)m_treeContainer.getParent(m_currentFolder);
          if (parentId != null) {
              Item resourceItem = m_treeContainer.getItem(parentId);
              if ((resourceItem.getItemProperty(CmsResourceTableProperty.PROPERTY_DISABLED).getValue() == null)
                  || !((Boolean)resourceItem.getItemProperty(
                      CmsResourceTableProperty.PROPERTY_DISABLED).getValue()).booleanValue()) {
                  // don't open disabled parent folders
                  try {
                      readFolder(parentId);
                      m_fileTree.select(parentId);
                  } catch (CmsException e) {
                      CmsErrorDialog.showErrorDialog(
                          CmsVaadinUtils.getMessageText(Messages.ERR_EXPLORER_CAN_NOT_READ_RESOURCE_1, parentId),
                          e);
                      LOG.error(e.getLocalizedMessage(), e);
                  }
              }
          }
      }
docs: Shows the parent folder, if available.<p>