woocommerce_product_query_meta_query │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_product_query_meta_query', 'wp_kama_woocommerce_product_query_meta_filter', 10, 2 );

/**
 * Function for `woocommerce_product_query_meta_query` filter-hook.
 * 
 * @param  $meta_query 
 * @param  $that       
 *
 * @return 
 */
function wp_kama_woocommerce_product_query_meta_filter( $meta_query, $that ){

	// filter...
	return $meta_query;
}

$meta_query

-

$that

-

Where the hook is called

return array_filter( apply_filters( 'woocommerce_product_query_meta_query', $meta_query, $this ) );

Where the hook is used in WooCommerce