Product Combo is similar to Bundles but they have a bit of another design and functionality. While bundles can be used to buy several products which are bundled together (for example main product and accessories), Product combos can be used only as paired products. You can add unlimited variations of combos. Each combo can have discount
Combos can be set for each product in Linked product section when you edit product data
Combos are available in two variants: as block which you can use in Product single templates or as tab. You can enable tab in Woocommerce – settings – Greenshift Combos
Discount is counted on both products: main and combo product