You can create a folder (\Sales) for the sales group, and another folder (\Support) for the support group. You can then share the folder \Sales to the sales group; and share the \Support folder to the support group. When sharing to a group of people, you can manually enter the users' email addresses / usernames directly in the share-to field. Or you can create a "Contact group" and then select the contacts from the contact list.
To create a contact group, please logon www.drivehq.com and go to DriveHQ email hosting service, click on Webmail, then click on Contacts.