Formbuilder field values in container (fieldset)

Hi @solverat, another formbuilder question…

Having some trouble getting a form field value (in and event listener) from a field that is a Fieldset container. Here is the basis for what I have -

$this->form = $event->getForm();

    foreach($this->form->getData()->getFields() as $field) {
        if ($field instanceof FormFieldContainer) {
            foreach($field->getFields() as $groupedField) {
                $value = $this->form->getData()->getFieldValue($groupedField->getName());
            }
        } 
    }

The key part here being $this->form->getData()->getFieldValue($groupedField->getName());

This does not get the submitted data the way it does with a non-grouped (or container) field.

Can you shed some light on this? Thank you!