The existence of intermediary institutions such as business incubators has become one of the solution models to support the creation of start-up companies. On the other hand, the role of start-up communities in supporting the entrepreneurial ecosystem cannot be ignored. However, very few discuss the synergistic role of the start-up communities with business incubators, especially in developing ecosystems. This study departs from the hypothesis that start-up communities around the university business incubators institution will increase the incubator's capacity to carry out its obligations to provide services to its fostered start-ups. In various situations, the start-up communities have fulfilled some of the needs for information sharing, network development, and the basic skills, etc., needed by start-up teams. On the other hand, University Business Incubators (UBIs) tend to be equipped with various facilities, access to funding, and access to formal networks in carrying out their mission. There are still few studies that discuss the interaction between these two agents in the innovation ecosystem. Ecosystem maturity is one of the keys to empowering start-up productivity, but there are more challenges in developing ecosystems. Therefore, the empowerment of reciprocal synergies between start-up communities and incubator institutions in developing ecosystems needs to be studied. This paper proposes a research framework and research agenda to fill this gap.