[{"_id":"621c6e805961def3332bcf97","title":"monk plus","brand":"venture electronics","category":"earphones","variant":[{"price":455,"impedance":"16ohm"},{"price":1600,"impedance":"64ohm"}],"salesCount":185,"buysCount":182,"viewsCount":250},{"_id":"621c6dab5961def3332bcf92","title":"nokia1","brand":"nokia","category":"mobile phones","variant":[{"price":10000,"RAM":"4GB","ROM":"32GB"},{"price":15000,"RAM":"6GB","ROM":"64GB"},{"price":20000,"RAM":"8GB","ROM":"128GB"}],"salesCount":34,"buysCount":21,"viewsCount":80}]

db.collection.find({/** matching conditions*/"variant":{"$elemMatch":{"price":{"$gte":500,"$lte":1100}}}},{title:1,brand:1,category:1,salesCount:1,viewsCount:1,/** only return array elements that matched*/"variant.$":1})