This article presents two studies that examine the moderated multiple mediation model between Family Supportive Supervisors Behaviors (FSSB) and individual’s thriving at work through psychological availability and work–family enrichment at conditional levels of need for caring. Drawing on the Resource-Gain-Development framework and self-determination theory, the results of the 6-month time-lagged data demonstrate, in Study 1 (Italian sample = 156), that FSSB is associated with greater individual thriving at work via work–family enrichment and that this indirect relationship is significant exclusively for those who perceive a higher need for caring. In Study 2 (Chinese sample = 356), the results demonstrate the relationship between FSSB and thriving at work is serially mediated by both psychological availability and work–family enrichment at the conditional level of need for caring. In particular, the results demonstrate that individuals with a higher need for caring responded more favorably to the presence of a family supportive supervisor than those experiencing a lower need for caring. Implications for research and practice are discussed.