The persona approach is often treated as a single user-centered design method, but there are variations and adaptations for different design contexts which go beyond local customization. The paper discusses a set of dimensions and success criteria for describing the different persona uses, presenting a new framework. It then specifically investigates personas in the context of end-user development. Professional designers need to consider the design space for potential end-user tools. In addition they need to understand that their users are often designers themselves (they are designer-users), requiring that they also consider the design spaces of their users. Two-level personas are introduced to make professional designers more aware of such nested design spaces. A two-level persona consists of one first-level persona and a set of second-level personas to additionally represent complex designer-user relationships. The effectiveness of the approach is investigated in an exploratory empirical study. The results suggest that two-level personas add value when designing end-user design tools.