I'm trying to find a way to make a large CheckboxsetField display friendlier. Ideally I'd like to group them by their ParentID (with a divider, or even better, the title of each Parent ID over each set). Is there any (relatively simple) way to do something like that?

The CheckboxsetField is a collection of pages of a particular pagetype (Category) so they all have a ParentID Title

Hi Neil

the best option will be create custome field by extending CheckboxSetField, like below

class MyCheckboxSetField extends CheckboxSetField{
/**
* @todo Explain different source data that can be used with this field,
* e.g. SQLMap, ArrayList or an array.
*/
public function Field($properties = array()) {
Requirements::css(FRAMEWORK_DIR . '/css/CheckboxSetField.css');
your code here
========================
$properties = array_merge($properties, array('Options' => new ArrayList($options)));
return $this->customise($properties)->renderWith($this->getTemplates());
}
}

Also create MyCheckboxSetField.ss template file.

for more info, go to framework/forms/CheckboxsetField.php and see how it is done