db={jobs:[{_id:ObjectId("63db66479dd33ced5256b6ac"),manage_:[{createdAt:ISODate("2023-02-05"),userId:"63db66479dd33ced5256b6cc",contactedID:"a",listPosition:12,note:"something"},{createdAt:ISODate("2023-02-03"),userId:"userB",contactedID:"a",listPosition:12,note:"something else"}]},{_id:ObjectId("63db66479dd33ced5256b5ad"),manage_:[{createdAt:ISODate("2023-02-05"),userId:"63db66479dd33ced5256b6cc",contactedID:"a",listPosition:12,note:"something"}]},{_id:ObjectId("63db66479dd33ced5256b6ff"),manage_:[{createdAt:ISODate("2023-02-05"),userId:"userK",contactedID:"a",listPosition:12,note:"something"}]}],users:[{_id:ObjectId("63db66479dd33ced5256b6cc"),firstName:"a",lastName:"b",messages:[{_id:ObjectId("63db66479dd33ced5256b6ab"),userId:"userA",messageID:"m",jobId:"63db66479dd33ced5256b6ac",timestamp:ISODate("2023-02-04")},{_id:ObjectId("63db66479dd33ced5256b6a2"),userId:"userA",messageID:"m",jobId:"63db66479dd33ced5256b6ad",timestamp:ISODate("2023-02-03")},{_id:ObjectId("63db66479dd33ced5256b6ed"),userId:"userA",messageID:"m",jobId:"63db66479dd33ced5256b5ad",timestamp:ISODate("2023-02-04")},]}]}

db.users.aggregate([{$match:{_id:ObjectId("63db66479dd33ced5256b6cc")}},{$addFields:{jobIds:{$map:{input:"$messages",in:{$toObjectId:"$$this.jobId"}}}}},{$lookup:{from:"jobs",localField:"jobIds",foreignField:"_id",as:"jobs"}},{$set:{jobs:{$reduce:{input:"$jobs",initialValue:[],in:{$concatArrays:["$$value",{$cond:[{$in:[{$toString:"$_id"},"$$this.manage_.userId"]},[{$toString:"$$this._id"}],[]]}]}}}}},{$set:{messages:{$filter:{input:"$messages",cond:{$in:["$$this.jobId","$jobs"]}}}}},{$unset:["jobs","jobIds"]},{$merge:{into:"users"}}])