[{"records":[ISODate("2020-04-19T00:49:18.945Z"),{"date":ISODate("2020-05-07T04:49:55.643Z"),"text":"someText"}],}]

db.collection.aggregate([{$unwind:"$records"},{$match:{"records.text":{$exists:true}}},{$project:{_id:1,text:"$records.text"}}])