The goal of this work is to establish a simple and flexible construction method for reflective concurrent systems. In this paper, a novel method to construct a meta-level architecture for a group of actors is presented. The key idea is to apply parallel composition to actors that constitute the meta-level of the group. This results in a uniform construction method for various types of meta-level actors. The benefits of the proposed method is illustrated by giving a solution to a synchronization problem in actor-based context-oriented programming.