When you select the Group/Function Admin menu item or link, you first view a page called List Group. On this page is a list of all the user groups which have been created to date. Each of these groups pertains to only one of the organization types: Manufacturer, Payer or RebateWeb. This page allows you to create a new group (via the Add Group button), view or edit a particular group by clicking on the group name, delete the group (except the RWA group), or look at a list of functions.
View / Edit Group
Once you have clicked on the name of an existing group, you will go to the Group Details page. This shows you a list of the menus and the functions which are available to any user who is assigned this group. If you click on the Edit Group button from this page, you will arrive at a page which will allow you to change the menus and the security function list for the group. This should be done with great caution.
Add Group
If you click on the Add Group button from the List Group page, you will be allowed to create a new group. This page looks very much like the Edit Group page except that you need to supply the group name and type to begin with. I do not know whether there is any relationship enforced between security functions and menus or between either of those and Organization Type. To set up a new group will require even greater caution than to make a small change to an existing group.
Function List
On the Group List page, there is also a button called Function List. The List Function page shows each of the security functions which can be associated with a group. These can themselves be edited or viewed. This page also contains a Menu List button which brings up a list of menus; these too can be viewed or edited. Anything in this area should probably be changed only by the web developers.