<?php

$groups = array(
	array(
		'label' => '',
		'value' => ''
	),
	array(
		'label' => 'test',
		'value' => 'test'
	)
);

function validate($var)
{
	return !empty($var['label']);
}

$groups = array_filter($groups, 'validate');
foreach($groups as $a) {
	echo "<option value='".$a['value']."'>" . $a['label'] . "<option>";
}