In an increasingly volatile business environment, firms often face severe resource constraints. The interactions among stakeholders drive dynamic adjustments of firm boundaries and foster value co-creation. Existing studies, however, have insufficiently examined the interactive mechanisms linking human resource boundary evolution and value co-creation. This paper investigates Hema’s employee sharing model to explore how firms’ human resource boundaries evolve and interact with value co-creation across different stages, as well as the underlying decision logics. The findings reveal that in the emergency stage, firms adopt a resource bricolage strategy to expand human resource boundaries and achieve business value co-creation through value transformation driven by boundary enlargement. In the normalization stage, firms rely on digital platforms to implement resource-environment reconfiguration, achieving boundaryless human resource integration and realizing both business and social value co-creation through the synergistic expansion of scale and capability boundaries. The study further elucidates two decision logics of value co-creation: resource bricolage follows an effectual logic, whereas resource-environment reconfiguration follows a causal logic. The digital platform, through the evolutionary mechanism of “resource connection–collaboration–response–network,” acts as the key driver of firms’ logical transformation and value co-creation. This research provides new theoretical insights into how firms can construct value co-creation mechanisms and achieve strategic transformation from a resource-interaction perspective.