Once multiple products are set up under a single account mycompany.com pointing to (companyname.freshdesk.com), the different products could be identified by a vanity URL.
This vanity URL should point to the product's Freshdesk URL; i.e. if product1.companyname.com and product2.company.com are vanity URLs of the portal, then point the CNAME to companyname.freshdesk.com.
This will ensure that you have multiple brands from a customer's perspective, but all under the same Freshdesk account from an agent's point of view which increases the overall productivity.