remove_action('woocommerce_shop_loop_item_title','woocommerce_template_loop_product_title',10);
add_action('woocommerce_shop_loop_item_title','fun',10);
function fun()
{

echo 'custom_field_value';

}

add_filter( 'woocommerce_page_title', function() {
    echo 'custom_field_value';
} );