Set the page title

To utilize the page title feature, place the title Block within a Region of your Theme in the settings.js file.

With text

dg.setPageTitle(dg.t('Edit'));

With a widget

dg.setPageTitle({
  _theme: 'title',
  _title: dg.t('Edit'),
  _attributes: { class: ['clearfix'] },
  _prefix: dg.bl('<i class="fa fa-arrow-left"></i>', 'group/' + node.nid, {
    _attributes: {
      title: dg.t('Cancel'),
      class: ['pull-left']
    }
  })
});

You can use any widget, not just the title widget.