Check if a field group's subfields have values Is it possible to check if a fieldset's subfields have values?
If none of the fieldset's fields have values it would return null.

$field = field_get_items('node', $node, 'group_name');
if ($field) {
   // At least 1 of it's sub-fields has a value!
}
else{
   // None of it's subfields have values!
}
You might want to try use the field_group_field_group_is_empty() function.

From the field_group module itself:

  // Example from field_group itself to unset empty elements.
  if ($display) {
    foreach (element_children($element) as $name) {
      if (in_array($name, $groups)) {
        if (field_group_field_group_is_empty($element[$name], $groups)) {
          unset($element[$name]);
        }
      }
    }
  }