[{"_id":ObjectId("5ea0576c2671f799e1ad65db"),"model":"Volkswagen","make":"Volkswagen","year":1969,"mileage":15000.0,"vi_number":"ba37d9b98fe940dba100fdf0330c30f0","engine":{"horsepower":400,"liters":5.0,"mpg":20.0,"serial_number":"a9ff4120-ee34-4588-af1a-77f62457531f"},"service_history":[{"date":ISODate("2020-04-22T12:10:55.622Z"),"description":"Cleaning","price":150.0,"customer_rating":5},{"date":ISODate("2020-04-22T12:14:53.439Z"),"description":"Flat tire","price":100.0,"customer_rating":2},{"date":ISODate("2020-04-22T12:30:54.071Z"),"description":"Waxing","price":77.0,"customer_rating":4}]}]

db.collection.aggregate([{$unwind:"$service_history"},{$match:{"_id":ObjectId("5ea0576c2671f799e1ad65db")}},{$match:{$expr:{$lte:["$service_history.customer_rating",2]}}}])