This qualitative research study examines how Chicanx/Latinx student affairs professionals' experiences and concepts of belonging inform their practices as they support Chicanx/Latinx students at an emerging Hispanic-serving public research institution. I conducted six semi-structured interviews and two focus groups with a total of 13 Chicanx/Latinx student affairs professionals at UC Davis. CRT, LatCrit, and Hurtado et al.'s (2012) Multicontextual Model for Diverse Learning Environments were key frameworks used to analyze the data. The findings revealed that interview participants embraced situational concepts of belonging that happens in microclimates, but which is not generally felt at the institutional level. These concepts of belonging have been shaped by participants' experiences of marginalization and belonging in higher education, both as students and as professional staff. Motivated to improve Chicanx/Latinx college student experiences (Linder & Simmons, 2015; Urrieta, 2007), participants strive to foster culturally relevant microclimates of belonging and support within their departments. Five primary themes describe the ways in which Chicanx/Latinx student affairs staff influence belonging for Chicanx/Latinx students: (1) representation matters, (2) providing holistic interpersonal support, (3) implementing culturally relevant structural support, (4) collaboration and advocacy, and (5) assessment and adapting to students' needs. This study fills a gap in the literature on the perspectives and experiences of the Chicanx/Latinx student affairs practitioners who support Chicanx/Latinx students at an emerging HSI. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]