Database
[{userName:"Bob",userActivity:{"hourly":["2022-05-09T02:31:12.062Z","2022-05-09T19:37:42.870Z"]}},{userName:"Bob",userActivity:{"hourly":["2022-05-09T02:31:12.062Z","2022-05-13T15:37:42.870Z"]}}]
Query
db.collection.aggregate([{$set:{max:{$max:{$map:{input:"$userActivity.hourly",in:{$max:"$$this",},},},},},},{$match:{max:{$gte:"2022-05-13T11:37:42.870Z",},},},{$unset:"max",},])