Filtering a region by combination of AND and OR

I'm just wondering if anyone can help or has found a way to filter perch_content_custom with a combination of AND and OR. I am filtering by 2 values, which works well, but I want to be able to filter items that have the first value and the second value as one option or another.

So basically this... what=$what AND where=$where OR where2=$where

This is the current code I have which doesn't include the second 'where'.

$filters = array();
$what = perch_get('what');
$where = perch_get('where');

if (!empty($what)) {
    $filters[] = array(
        'filter' => 'what',
        'match'  => 'eq',
        'value'  => $what,
    );
}

if (!empty($where)) {
    $filters[] = array(
        'filter' => 'where',
        'match'  => 'eq',
        'value'  => $where,
    );
}

if (!count($filters)) $filters=false;

perch_content_custom('Business Listings', array(
    'template' => 'business_listing.html',
    'filter' => $filters,
));