[{"doc":{"k":"ABC","v":{"sec":0}},"info":[{"data":[{"k":"XYZ","v":{"know":"alpha"}},{"k":"ABC","v":{"know":"alpha"}}]}]}]

db.collection.aggregate([{$set:{info:{$map:{input:"$info",in:{data:{$filter:{input:"$$this.data",cond:{$eq:["$doc.k","$$this.k"]}}}}}}}}])