In current days, the business environment is more competitive and changing faster than ever before, so it is important for employees to learn new knowledge related to their business quickly and efficiently. Meanwhile, the personalized e-learning system makes it possible for employees to discover a personalized learning path in order to improve the learning efficiency. For business in a company, it is often required a group of people to complete a particular business task, however, the group members are not equipped with the same level of prior knowledge related to the task. Therefore, discovering a groupized learning path is important and necessary for employees working under collaborative business environment. In this paper, we focus on how to trace the roles of one employee in a group in order to establish the relationship between it and his knowledge level, and addressing the problem of improving the learning efficiency for a group of employees rather than a single person under the collaborative business environment. Based on the proposed model, an RLPD (role-based learning path discovery) algorithm is proposed to optimize the process for a group of employees to grasp new knowledge related to a certain business task more efficiently and effectively, and its superiority has been proved by our experimental works.