Emerging youth movements to promote issues reflected in the United Nations Sustainable Development Goals (SDGs) are celebrated as critical for the future attainment of societal aims. We explore the possibility for institutions of higher education to serve as an intentional "third space" to engender the creation and mobilization of "hybrid movements" that intentionally engage youth internationally. This case study interrogates the YouthMappers digital humanitarian mapping model of student-led, faculty-mentored, globally-networked chapters through a global survey of 205 participating students from 32 countries. Results indicate the extent to which youth reflect on skill-development versus global citizenship, and how they understand the meanings of their actions for SDGs, locally and globally. Detected differences by gender, world region, and duration of participation are interpreted and validated with additional qualitative data. We conclude with observations about how universities can open enabling spaces for youth action on SDGs.