One of the great SCVMM features is the ability to simply, create a "Host Group" under the "Managed Computers" object. In this example I have created two sub groups, the one I'll detail here is UK, I could also create child groups under these parents.
When you look at the properties of this group, you can edit the name, change the path and see which users or groups are members (more of that later)
The next Tab lets you set what are called now "Self-Service" policies, this is the feature that defines what options can be used when using the self-service portal. First of all I need to add a user or group, in my case I added the user "Clive Watson". If you don't need to use the portal, just use the groups to logically define your groupings.
In the next screen you get to simply check the operations you wish to allow for the user when they visit the self-service portal. These attributes apply to the defined users in this container or Host Group, so you could allow a set of non power users just the ability to start, stop, pause, resume and VMRC (remote control) a Virtual Machine.
For multinational organisations you may wish to define host groups as I have done in this example by geographic location, such as UK, you can then create sub groups such as London and Reading. You may also wish to create groups per function, such as DEV as a top level group (parent) and child groups like "DEV TEAM A" etc...
Remember a server host can only be a member of one group, so careful planning is advisable.