Since degrees are entered as separate education relationships, create a constituent query with the following criteria:

Relationships, Education, Total Education greater than 1
AND Education School Name equals [shool name]
AND Education Primary Alumni Information equals Yes
 
 
If you don’t use the Primary Alumni Information in education records, this will not work.
 
If the Degrees need to be all from the SAME school, then the criteria will be this:

AND (Primary Education School Name equals XYZ
AND Primary Education Degree not blank
AND Total Education greater than 1)
AND (Education School Name equals XYZ
AND Education Degree not blank
AND Education Primary Alumni Information equals No)

Note the location of the parenthesis and the use of Primary Education fields AND Relationship Education fields.  
Output the Degree from Query Fields node in the output tab.
If a record has multiple non-Primary Education Relationships to school XYZ, they will appear multiple times in the query results.