List elements can be ordered or unordered. To make a nested list, create another list inside the list element (nested list) like so:

<ul>  
	<li>test</li>  
	<li>test2  
		<ul>  
			<li>test2.1</li>  
			<li>test2.2</li>  
		</ul>  
	</li>  
</ul>