Create private folder for Drupal website

On our Drupal website we have a consultant portal where you have to be assigned a specific role to be able to log in. Similarly we folder named Private where any items in it can only be viewed once logged in to the portal. We added a new role - "business affiliate", which only has access to a segment of the consultant portal content. What we need is to be able to restrict access to a segment of the items in the Private folder - either by adding another level of access for just those Business Affiliates, OR, possibly easier - create a second private folder just for business affiliates.