I'm trying to make a Customer Portal for a customer, that would allow Project access to our customers. One of the requirements of the portal is that the customer should be able to create tasks and attach them to the members of the project.

How can I modify the "Portal Personal Contacts" (That allows only access to the own partner in the Portal) record rule such that it would allow access to the other members of the team?

Here it is:
Object: Partner

Rule definition: [('message_follower_ids','in',[user.partner_id.id])]