-\n([^(]+)(\(\d\))[|]([^-]+)

Collect all match groups then write additional regex to key value them. The match groups that have OR must be processed further:

MATH 45    DIFFERNTL EQUATN SCI+ENGR  (3)|MATH 295    Differential Equations (3)
                                         |   OR 
                                         |MATH 287    Introduction to Linear (5)
                                         |            Algebra and 
                                         |            Differential Equations