Background: Academic libraries of this age have embraced the user-centric approach and introduced learning commons (LC) for interactive learning of its users. They are redesigning their resources and services to meet the diverse learning needs of the Techie Gen LC users. It is an out of class group learning space where users are sharing and acquisitioning knowledge for solving learning problems. Group learning is supported by Problem-Based Learning (PBL) cycle phases where users play a knowledge transformer role. This study checks the relation and the ways that knowledge sharing and acquisition supports PBL phases and thereby confirms a new PBL phase. Objective(s): The main aim of the study is to investigate the relation and support of knowledge sharing and acquisition in problem-based learning (PBL) phases and thus determine a new PBL phase for LC. Methods: The research used a quantitative approach and included a survey design in its methodology. The online surveys were conducted in three university libraries of Japan and statistical analysis of simple percentage, mean and standard deviation were adopted to analyze the data. Results: The Cronbach's alpha score of the construct of knowledge sharing and acquisition was 0.750, skewness -0.531 and kurtosis was 0.651, which reveals it`s strong validity. Moreover, 77.5% of participants perceived that knowledge sharing and acquisition has a positive influence on them in PBL supported group learning at LC. Conclusion: The results of the study has revealed that knowledge sharing and acquisition is a new PBL cycle phase for LC group learning. Therefore, LC must combine resources and services in order to foster knowledge sharing and acquisition in PBL supported group learning and thus leverage users' out of class activities.