How to match more than one value when filtering

I have a testimonial area on most pages across a site. I've created a region on index.php using perch_content_create and then used perch_content_custom to filter and sort testimonials.  

index.php page

<?php perch_content_create('Testimonials', array(
    'template' => 'testimonial-section.html',
    'multiple' => true,
));
?>

Within testimonial-section.html I've included a select field type so that I can display relevant testimonials on a page:

<perch:content id="testimonial_type" type="select" label="Type of testimonial" help="Select the category that most closely describes the type of testimonial" options="Healthcare, Charity, Voluntary, General" allowempty="false" required="true" suppress="true" /> 

Most of the time, I just want to filter by testimonial type and match one value. e.g. 

<?php perch_content_custom('Testimonials', array(
  'page' => '/index.php',
  'template' => 'testimonial-section.html',
  'filter' => 'testimonial_type',
  'match' => 'eq',
  'value' => 'Healthcare',
  'sort' => 'testimonial_type',
  'sort-order' => 'RAND',
  'count' => '1',
)); ?>

In some circumstances I'd like to match by more than one value, for example, display a testimonial either from Charity or Voluntary testimonial type. How would I do this please?

Thanks