Hi Jared,
just add the condition at the end of the .or chain like so:
wixData.query('collection')
.contains('field1', value1)
.or(wixData.query().contains('field2', value2))
.eq('field3', value3)
.find()
The query is “field3 is equal to value 3 AND either field1 contains value 1 OR field2 contains value2”.
Bonus tip - specifing collection name in inner query (the one you pass to .or(…)) is optional.
I hope this helps. Let me know!