Have some restriction clarity on security

Assuming "products" are in a UD dimension, you can rely solely on their entity security to allow them access to view all data associated with that entity.

They will need the following:

1. Access to an application (open application security role)
2. Access rights to the cube (Access Group on the cube)
3. Read rights to the entity (Read Data Group on the entity)
4. Read rights to a scenario(s) of data (Read Data Group on the scenario)
5. Access rights to a WF (Access Group to an WF profile)

So there are several pieces to granting that individual user access to one entity and all products.  Typically you will have a security group that includes these 5 pieces and then you put your user in that 1 group.