Not my default, you would need to modify the theme via a child theme. We supply this in the main zip file. Once installed and activated, you can use something like this to modify WooCommerce shop loop: http://stackoverflow.com/a/30561683/4034148
add_filter( 'pre_get_posts', 'catalog_filters' );
function catalog_filters( $query ) {
if ( $query->is_main_query() && $query->post_type = 'product' ) {
if(isset($_GET['onsale'])) {
$meta_query = array(
'relation' => 'OR',
array( // Simple products type
'key' => '_sale_price',
'value' => 0,
'compare' => '>',
'type' => 'numeric'
),
array( // Variable products type
'key' => '_min_variation_sale_price',
'value' => 0,
'compare' => '>',
'type' => 'numeric'
)
); $query->set('meta_query', $meta_query);
}
if(isset($_GET['bestsellers'])) {
$meta_query = array(
array(
'key' => 'total_sales',
'value' => 0,
'compare' => '>',
'type' => 'numeric'
)
);
}
}
return $query;
}
.