<?php $categories = $this->params->get('categories'); 
foreach($categories as $category) :  ?>
<li class="button"><a href="#" data-filter=".<?php echo $category; ?>"><?php echo $category; ?></a></li>
<?php endforeach; ?>

<?php $categories = $this->params->get('categories'); 
foreach($categories as $category) :  ?>
<li class="button"><a href="#" data-filter=".<?php echo $category->name; ?>"><?php echo $category->name; ?></a></li>
<?php endforeach; ?>

<ul>
	<?php foreach($this->subCategories as $key=>$subCategory): ?>
	<li class="button"><a href="#" data-filter=".<?php echo $subCategory->name; ?>"><?php echo $subCategory->name; ?></a></li>
	<?php endforeach; ?>
</ul>