Navigation only showing one level from current page

I'm trying to show all sub-pages and their sub-pages within a navigation from a given page.

The hierarchy is as follows:

Portfolio

Portfolio Sections

Portfolio Items

I'm trying to show a 2 tier menu on the portfolio page (sections then items). On the portfolio page I have the following code:

<?php perch_pages_navigation(array(
    'levels'=>2,
    'template' => array('portfolio_sections.html','portfolio_items.html'),
    'from-path'  => '*',
    'from-level' => 1,
    'hide-extensions' => true,
)); ?>

However I'm only getting the first level returned using the 'portfolio_sections.html' the pages that sit under these sections are not being returned by the menu.