problem with subtotal calculation

We use the WooCommerce norm to display and caluclate subtota for each iteml:

apply_filters( ‘woocommerce_cart_item_subtotal’, WC()>cart>get_product_subtotal( $_product, $cart_item[‘quantity’] ), $cart_item, $cart_item_key );

We are also using discounts (which are calculated well). But subtotals are wrong for individual items.

Subtotal is calculated as: discounted price x exchange fee x exchange rate x quantity

…the problem is that discounted price has already calculated within it, the exchange fee and exchange rate.

How can we solve this issue using standard woocommerce norm?