To show customers the total discount applied to their order in the WooCommerce cart and checkout, you can use the woocommerce_cart_totals_before_order_total and woocommerce_review_order_before_order_total hooks. Step 1: Open your active theme’s functions.php file. Step 2: Add the following code:

// Display total savings in cart and checkout
function display_total_discount() {
    $total_discount = WC()->cart->get_cart_discount_total();

    if ($total_discount > 0) {
        $formatted_discount = wc_price($total_discount);
        echo '<tr class="total-discount"><th>' . __('Total Discount', 'your-text-domain') . '</th><td data-title="' . __('Total Discount', 'your-text-domain') . '">' . $formatted_discount . '</td></tr>';
    }
}
add_action('woocommerce_cart_totals_before_order_total', 'display_total_discount');
add_action('woocommerce_review_order_before_order_total', 'display_total_discount');

Step 3: Save and upload the file back to your server. Now, the cart and checkout tables will display a new row labeled "Total Discount" that reflects the applied discount amount. Make sure to style the output to match your theme, and change the 'your-text-domain' to your theme or plugin’s actual text domain.