db={Orders:[{"_id":"628216b7b30bb8aa80c8fd1a","promotionsDetails":{"companyTotalPrice":27,"promotionsData":[{"_id":"621de063bb5f9f0bf510897f","price":27,"companyId":"621dd85eb45ca2ae292d9a36"},{"_id":"621de063bb5f9f0bf510897d","price":19,"companyId":"621dd85eb45ca2ae292d9a32"}]}},{"_id":"628214fcb30bb8aa80c8fd18","promotionsDetails":{"companyTotalPrice":46,"promotionsData":[{"_id":"621de063bb5f9f0bf510897f","price":46,"companyId":"621dd85eb45ca2ae292d9a32",}]},}],Company:[{"_id":"621dd85eb45ca2ae292d9a36","title":"example"},{"_id":"621dd85eb45ca2ae292d9a32","title":"example2"}]}

db.Orders.aggregate([{$unwind:"$promotionsDetails.promotionsData"},{"$lookup":{"from":"Company","localField":"promotionsDetails.promotionsData.companyId","foreignField":"_id","as":"promotionsDetails.promotionsData.companyData"}},])