Exposing data sources through Daas (Data as a Service) services become increasingly important. The DaaS service discovery constitutes a real challenge in P2P environments. Although several data source discovery methods take into account the semantic heterogeneity problems by using several domain ontologies (DOs), most of them imposed a topology on the graph formed by DOs and mapping links. In this paper, we propose a DaaS Service Discovery (DSD) method without imposing any topology on this graph. Peers, using a common DO, are grouped in a Virtual Organization (VO) and connected in a Distributed Hash Table (DHT). Then, lookups within a same VO consists in a classical search in a DHT. Regarding the inter-VO discovery process, we propose an addressing system, based on the existing mapping links between DOs, to interconnect VOs. Furthermore, a lazy maintenance is adopted in order to reduce the number of messages required to update the system.