Database
db={"collectiona":[{"_id":"6173ddf33ed09368a094e68a","title":"a"},{"_id":"61wefdf33ed09368a094e6dc","title":"b"},{"_id":"61wefdfewf09368a094ezzz","title":"c"},],"collectionb":[{"_id":"6173ddf33ed0wef368a094zq","collectionaID":"6173ddf33ed09368a094e68a","data":[{"userID":"123","visibility":false,"response":false},{"userID":"2345","visibility":true,"response":true}]},{"_id":"6173ddf33ed09368awef4e68g","collectionaID":"61wefdf33ed09368a094e6dc","data":[{"userID":"5678","visibility":false,"response":false},{"userID":"674","visibility":true,"response":false}]}]}
Query
db.collectiona.find()