[{"_id":"1.1000038","recomendation":["1.6739718"]},{"_id":"1.1000069","recomendation":["1.9185509","1.9051998","1.9034279","1.8288046","1.8152670","1.858775","1.6224229","1.4591674","1.3862464","1.3427739","1.3080062","1.3003608","1.1694619","1.1634683","1.1590664","1.1524146","1.754599","1.700837","1.763617"]}]

db.collection.aggregate([{"$match":{"_id":{"$in":["1.1000069","1.1000038"]}}},{"$project":{"recom":{"$arrayElemAt":["$recomendation",0]}}}])