LISTAGG on Calculated Column

Hi. I'm trying to do listagg on a calculated column. Unsure of the syntax. Thanks!

LISTAGG(STDNT_GROUP,';') WITHIN GROUP (ORDER BY EMPLID) FROM UG GROUP BY EMPLID

Not a TDP specific question, but these examples from Oracle's docset might help:
https://docs.oracle.com/cd/E11882_01/server.112/e41084/functions089.htm#SQLRF30030