[{name:"Sam",specs:[{city:"istanbul",color:"blue"},{city:"istanbul",color:"black"},{city:"izmir",color:"yellow"}]},{name:"Sam",specs:[{city:"istanbul",color:"yellow"},{city:"istanbul",color:"black"},{city:"izmir",color:"yellow"}]}]

db.collection.aggregate([{$match:{"specs.city":"istanbul","specs.color":"blue"}}])