In the context of complex and digitalized engineering projects, effectively orchestrating meta-knowledge that encompasses awareness of diverse expertise presents a significant challenge, as it requires crossing various boundaries. Situated expertise plays a critical role in this process, connecting individual or group-level meta-knowledge to wider expertise systems in projects. We report a case study exploring how group expertise boundaries influence situated expertise development in the oil and gas front-end project context. Through qualitative analysis, we underscore the role of permeable group expertise boundaries in fostering open situated expertise systems, allowing for meta-knowledge about individuals, groups, and digital technologies. This permeability is especially critical in innovative and non-contractual contexts. We identify four elements—strategy, structural design, interaction molding routines and roles, and digital boundary objects—that contribute to open situated expertise development. Our findings show that while digital boundary objects can mediate expertise boundaries by enabling communication and navigation of expertise in projects, the reach of situated expertise largely depends on interaction molding elements, particularly boundary-spanning roles. This study concludes by recommending that practitioners expand their meta-knowledge, rethink their strategic approaches to situating and utilizing expertise in projects, and carefully establish routines for using digital technologies to record and retrieve expertise.