[{"callId":"17dac51e-125e-499e-9064-f20bd3b1a9d8","caller":{"firstName":"Test","lastName":"Testing","phoneNumber":"1231231234"},"inquiries":[{"inquiryId":"b0d14381-ce75-49aa-a66a-c36ae20b72a8","routeHistory":[{"assignedUserId":"cfa0ffe9-c77d-4eec-87d7-4430f7772e81","routeDate":"2020-01-01T06:00:00.000Z","status":"routed"},{"assignedUserId":"cfa0ffe9-c77d-4eec-87d7-4430f7772e81","routeDate":"2020-01-03T06:00:00.000Z","status":"ended"}]},{"inquiryId":"9d743be9-7613-46d7-8f9b-a04b4b899b56","routeHistory":[{"assignedUserId":"cfa0ffe9-c77d-4eec-87d7-4430f7772e81","routeDate":"2020-01-01T06:00:00.000Z","status":"routed"},{"assignedUserId":"cfa0ffe9-c77d-4eec-87d7-4430f7772e81","routeDate":"2020-01-03T06:00:00.000Z","status":"ended"}]}]}]

db.collection.aggregate([{$addFields:{inquiries:{$map:{input:"$inquiries",as:"inquiry",in:{inquiryId:"$$inquiry.inquiryId",routeHistory:{$filter:{input:"$$inquiry.routeHistory",cond:{$eq:[{$max:"$$inquiry.routeHistory.routeDate"},"$$this.routeDate"]}}}}}}}}])