The SINFONICA project aims to develop innovative strategies, methods, and tools to engage CCAM users, providers, and other stakeholders to collect, understand and structure their needs and concerns. This is only possible with the constant involvement of citizens, future users, stakeholders, and service providers linked to CCAM. But how can we be sure that every category is correctly represented? That every voice, every thought, every opinion is expressed and heard? This paper presents a methodology for defining the research groups and so-called groups of interest which is based not just on the analyses of the literature and projects, but also on the involvement of four municipalities across Europe which offer an immersed view within their reality. With numerous geographical, structural, and cultural differences, these municipalities are involved in the co-definition of the research groups and groups of interest so that each group can give voice to all the ones that need to be represented. The results presented in this paper summarize the process of the co-creation of the research groups and groups of interest, their final composition as well as the participatory approaches that will be used with the different categories.