You would need to add a persona role in order for them to have access to the Groups navigation in the navigation bar. To add this the best suggestion is to add the Friend Role. This way they do not have access to everything any other Role has access to.

To add a Role or Roles take the following steps:

 

  1. Navigate to Core
  2. Security > Select Roles
  3. Select the preferred role (the one that will be added to the user)
  4. Select Members
  5. Select Add
  6. Search for the preferred user > Select the >> to add the user 
  7. Select Save & Exit


Or

  1. Navigate to Core
  2. Using People Finder, search for and select the preferred user
  3. Select the Access Tab
  4. Select Role Membership
  5. Select Edit
  6. Select the preferred Roles 
  7. Select Save and Exit

To Clone a Role, see How do I create a clone of a role?