Hello, 

I am trying to set up a customer portal to our business partners. My example is very similar to the one described in the zoho crm article about portals: "The franchise owners can request to view their outlets' performance and their customers' details. You can create exclusive portals for the franchise owners. They will be able to view and edit the relevant records right from the CRM." 
In my case I wanna give access to customers for them to see all contacts we have from the same account. 
Example: Customer John Doe, owner of Company 1, to have access to all contacts in the CRM from the same account "Company 1". That way he can update and change the contacts in case they leave his/her company, change address and etc. 

It sounds like something straightforward but I can't seem to find a way to do this, even chatted with zoho but without a clear answer so far. So felt like asking the community.

Thank you!!!!