This study aims to investigate how middle managers help subordinates expand their successes, drawing on experiential learning theory and the broaden-and-build theory. Using an open-ended survey of middle managers (n = 203) working for a global manufacturer of motor vehicles and parts in Japan, the grounded theory approach was used to develop the model of experiential learning support for expanding successes. The results suggest that managers tend to help their subordinates review and expand their successes through four phases that consist of recognition and acceptance, analysis (causal analysis, generalisation, and improvement) sharing (documentation and standardisation and knowledge sharing) and application (stretched assignments and action plan). This study contributes to the literature on Human Resource Development by identifying positive instructional methods for developing employees.