This essay reports on engaging academic and community partners whose positionalities spanned diverse lived experiences and power structures. Using groundwork from several literatures, we reflect on developing, nurturing, repairing, and expanding a container as a critically reflective space for experimenting with new ways of being and doing. A well-curated and nurtured container creates processes and spaces where group members feel they belong; they commit to practice a shared set of agreements, and work through interpersonal and organizational conflict that will inevitably arise. The container can be an instrument for identity, organizational, and tactical boundary spanning. As a microsystem, a container can mobilize collective engagement when team members reflect diverse identities, hierarchies, and roles within the academic system and partnering communities. Theorizing the container as an opportunity structure for boundary spanning may help those advancing diversity, equity, inclusion, and justice (DEIJ) within academic land-grant institutions, university-community collaboratives, and community-based organizations.