The customer portfolio function allows you to assign your customers to various groups which in turn can be assigned to strategies or allow you to filter by a certain customer portfolio.
In addition, customer portfolios can be restricted to users i.e. if you have several credit controllers or a sales team that should only have access to certain clients, then this function is for you.
Please note for the restriction to work the user needs to have Member or Viewer permissions. Admin users will always see all of the customers.