[{"numbers":[2,8,15]},{"numbers":[4,8,9,13]},{"numbers":[1,3,7]}]

db.collection.aggregate([{$project:{_id:0,filtered:{$filter:{input:"$numbers",as:"num",cond:{$gte:["$$num",5]},}},mapped:{$map:{input:"$numbers",as:"num",in:{$multiply:["$$num",2]}}},reduced:{$reduce:{input:"$numbers",initialValue:0,in:{$sum:["$$value","$$this"]}}}}}])