[{"tag":"abc","created_at":new Date("2020-02-05T14:20:52Z"),"likes":12,"comments":3},{"tag":"abc","created_at":new Date("2020-02-04T14:20:52Z"),"likes":10,"comments":1},{"tag":"abc","created_at":new Date("2020-01-04T14:21:52Z"),"likes":12,"comments":3},{"tag":"abc","created_at":new Date("2020-01-04T14:22:52Z"),"likes":2,"comments":1},{"tag":"xyz","created_at":new Date("2020-01-04T14:22:52Z"),"likes":2,"comments":1},{"tag":"xyz","created_at":new Date("2020-01-05T14:22:52Z"),"likes":2,"comments":1}]

db.collection.aggregate([{$facet:{day_wise:[{$group:{_id:{tag:"$tag",day:{$dateFromParts:{year:{$year:"$created_at"},month:{$month:"$created_at"},day:{$dayOfMonth:"$created_at"}}}},likes:{$sum:"$likes"},comments:{$sum:"$comments"}}},{$project:{_id:"$_id.tag",likes:1,comments:1,dayMonthYear:{$dateToString:{date:"$_id.day",format:"%Y-%m-%d"}},day:"$_id.day"}}],month_wise:[{$group:{_id:{tag:"$tag",month:{$dateFromParts:{year:{$year:"$created_at"},month:{$month:"$created_at"}}}},likes:{$sum:"$likes"},comments:{$sum:"$comments"}}},{$project:{_id:"$_id.tag",likes:1,comments:1,monthYear:{$dateToString:{date:"$_id.month",format:"%Y-%m"}},month:"$_id.month"}}],tags:[{$group:{_id:"$tag"}}]}},{$unwind:"$tags"},{$project:{_id:"$tags._id",day_wise:{$filter:{input:"$day_wise",as:"item",cond:{$eq:["$tags._id","$$item._id"]}}},month_wise:{$filter:{input:"$month_wise",as:"item",cond:{$eq:["$tags._id","$$item._id"]}}}}},{$project:{_id:1,day_wise:{likes:1,comments:1,dayMonthYear:1},month_wise:{likes:1,comments:1,monthYear:1},}}])