Database

[{"_id":{"$oid":"5e636c552b872f00178033bf"},"finance":{"expenditure":[{"status":true,"_id":{"$oid":"5e636d442b872f00178033d4"},"amount":{"$numberInt":"900"},"category":"Coffee"},{"status":true,"_id":{"$oid":"5e636d492b872f00178033d5"},"amount":{"$numberInt":"1000"},"category":"Coffee"},{"status":true,"_id":{"$oid":"5e636d532b872f00178033d6"},"amount":{"$numberInt":"3000"},"category":"Sport"},{"status":true,"_id":{"$oid":"5e636d572b872f00178033d7"},"amount":{"$numberInt":"1000"},"category":"Sport"},],"customcategories":[{"budget":{"$numberInt":"200"},"_id":{"$oid":"5e636c552b872f00178033c7"},"title":"Sport"},{"budget":{"$numberInt":"100"},"_id":{"$oid":"5e636c552b872f00178033c8"},"title":"Coffee"}]}}]

Query

db.collection.aggregate([{$match:{_id:ObjectId("5e636c552b872f00178033bf")}},{$unwind:"$finance.expenditure"},{$match:{"finance.expenditure.status":true}},{$sort:{"finance.expenditure.currentdate":-1}},{$group:{_id:"$finance.expenditure.category",amount:{$sum:"$finance.expenditure.amount"},categories:{$first:"$finance.customcategories"}}},{$project:{_id:0,category:"$_id",amount:1,budget:{$arrayElemAt:[{$map:{input:{$filter:{input:"$categories",cond:{$eq:["$$this.title","$_id"]}}},in:"$$this.budget"}},0]}}}])

Result