Woocommerce Custom Rewrite Rules Array – Subcategories

Try this

add_filter( 'rewrite_rules_array', function( $rules )
{
    $new_rules = array(
        'services/([^/]*?)/page/([0-9]{1,})/?$' => 'index.php?product_cat=$matches[1]&paged=$matches[2]',
        'services/([^/]*?)/?$' => 'index.php?product_cat=$matches[1]',
        'services/([^/]*?)/([^/]*?)/?$' => 'index.php?product_cat=$matches[2]'
    );
    return $new_rules + $rules;
} );