Database
[{"_id":ObjectId("6375dbf89a70ce15b7c51172"),"title":"Visualizing Graphs and Clusters as Maps","year":2005,"name":"amir"},{"_id":ObjectId("6375dbf89a70ce15b7c5118a"),"title":"Visualizing Dynamic Data with Maps","year":2012,"name":"amir"},{"_id":ObjectId("6375dbf89a70ce15b7c511ac"),"title":"Visualizing Cartograms: Goals and Task Taxonomy","year":2015,"name":"kobourov"},{"_id":ObjectId("6375dbf99a70ce15b7c60293"),"title":"Upward straight-line embeddings of directed graphs into point sets","year":2008,"name":"hossain"},{"_id":ObjectId("6375dbf99a70ce15b7c738c7"),"title":"Upward straight-line embeddings of directed graphs into point sets","year":2010,"name":"hossain"}]
Query
db.collection.aggregate([{$sort:{year:-1}},{$group:{_id:{title:"$title",name:"$name"},year:{$first:"$year"}}}])