Assign technician group based on template

Assign technician group based on template

I tried to set up a business rule and a trigger and neither allows me to select a template that is a service request. 
On a trigger I can get the service template, but field update of the "technician group" is not there
On a business rule I can't select a service template. Its only showing the incident templates.

Does this need to be scripted and if it does, can you please provide script.
Thanks!
Jeff

                  New to ADSelfService Plus?