Role-based training refers to training that is customized to the specific role that an employee holds in the organization. For example, a salesperson may be required to attend a program that is specifically geared towards designing and delivering presentations on the specifications of the product line, as opposed to a "generic" presentation skills course.
Typically, companies that provide role-based training consult with the organization to have a full appreciation for the skills and competencies required in a particular role within the organization. Another example would be to train call center personnel in a customized manner depending on whether their role involves handling inbound or outbound calls, sales, customer service, etc.
I hope that helps.