In Magento 2 Marketplace, the sellers can add related and other associated products. For this, the admin first needs to allow the sellers from the backend as per the below image.

On the configuration page, the admin will set the following fields to Yes –

• Allow Seller to Add Related Products
• Allow Seller to Add Up-Sell Products
• Allow Seller to Add Cross-Sell Products

Now, the sellers can add the Related, Up-Sell Product and Cross-Sell Products while adding a product.

On the frontend, the customers can view the related and Up-Sell products on the product page.

And Cross-Sell products on the checkout page.

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