The phrase "underlying purposes" refers to the reasons or motivations that are hidden beneath the surface, and which may not be immediately apparent. Full definition
While it has a greater underlying purpose, it enhances employee communication and creates a memorable social experience that defines, to a degree, employee satisfaction within the company. (inc.com)
They share the same underlying purpose: to establish and understand where students are in their learning. (teachermagazine.com.au)
With the birth of the «schooling - instructional» paradigm, nurture became the dominant underlying purpose in the rhetoric of Roman Catholic and mainline Protestant church education. (religion-online.org)