Database

[{_id:"5ea5b78757447f3ee02f19eb",hour:[{_id:"5ea5b78857447f3ee02f19ee",hour_time:"15",pricea:30,priceb:25},{_id:"5ea5b78857447f3ee02f19ed",hour_time:"30",pricea:25,priceb:35},{_id:"5ea5b78857447f3ee02f19ef",hour_time:"40",pricea:15,priceb:50}]},{_id:"5ea5b78757447f3ee02f19ec",hour:[{_id:"5ea5b78857447f3ee02f19fe",hour_time:"25",pricea:40,priceb:25},{_id:"5ea5b78857447f3ee02f19fd",hour_time:"30",pricea:25,priceb:35},{_id:"5ea5b78857447f3ee02f19ff",hour_time:"40",pricea:15,priceb:50}]},{_id:"5ea5b78757447f3ee02f19fc",hour:[{_id:"5ea5b78857447f3ee02f19fa",hour_time:"15",pricea:20,priceb:25}]}]

Query

db.collection.find({"hour.hour_time":"15",$and:[{"hour.pricea":{$gte:30}},{"hour.priceb":{$lte:30}}]})

Result