This service sub-type tracks the role assigned to each employee involved in the opportunity. These records appear on an Opportunities record's Roles tab. See Roles Tab. Roles Form 
General Tab
Employee (
...
Required)
The name of the employee assigned to the role. This field links to the Employees service.
Start Date (
...
Required)
The date the employee assumed this role.
End Date
The date the employee ended this role.
Selling Role Type (
...
Required)
Specifies the employee's role in the opportunity. This field links to the Selling Role Types service. See About the Selling Role Types Form.
Split Commission Percent (
...
Required)
The percentage of the commission to be received by the employee if the opportunity is won.
Description
A brief description of the role.