Database

[{"id":1,"data":[{"val1":"xyz","val2":"abc"},{"val1":"a","val2":"b"}]},{"id":2,"data":[{"val1":"d","val2":"e"},{"val1":"f","val2":"f"}]},]

Query

db.collection.find({"$and":[{"data.0.val1":{$eq:"xyz"}},{"data.0.val2":{$eq:"abc"}}]})

Result