If you ever need to offer a product in a WooCommerce product tab inside another product you are in luck. This can be done with a WooCommerce shortcode
Now if you also want the customer to be able to add this product to the cart you can add a cart button and connect it to the product id like so
Shortcode details at https://docs.woocommerce.com/document/woocommerce-shortcodes/3-1-earlier/#section-6
