Increasingly, Dynamically Adaptive Systems (DASs) are addressing complex problems that require a high degree of assurance. The inherent complexity of DASs and the safety critical applications they are addressing necessitates rigorous requirements engineering (RE). This problem is further complicated by the multiple stakeholders involved in the RE process. Berry et al. have identified four levels of RE done for a DAS, in which each level implicitly corresponds to the objectives of a different stakeholder. This paper presents a goal-oriented approach to specifying the four levels of RE using the KAOS specification language. This approach enhances the understanding of the role and contributions of each stakeholder and their complex relationships.