What is the difference between 大学的二年级学生 and 大学二年级的学生?
The 的 in the two sentences have different functions

[大学的] + [二年级学生] --&gt; [of the university] + [the second-year students] = &quot;the second-year students of the university&quot; (的 here is a possessive marker that indicates the university possess the second-year students)

[大学二年级的] + [学生]--&gt; [of the second-year class in the university] + [students] = &quot;the students of the second-year class in the university&quot; (的 here is an adjective marker that marks 'the second-year class' as an adjectival phrase that describes the students. It can be reduced to '大学二年级学生' because unlike the possessive 的, the adjectival 的 is often omitted


Example sentence:
我們大学的二年级学生有一半是外國人 (Half of the second-year students in our university are foreigners)
小張是一名大学二年级(的)学生 (Xiao Zhang is a second-year university student)