db={"pages":[{/** ....*/Urls:[{IncomingUrl:"test1",status:"active"},/** ...*/],DraftUrls:[{IncomingUrl:"test2",status:"inactive"},/** ...*/]},{/** ....*/Urls:[{IncomingUrl:"test4",status:"active"},/** ...*/],DraftUrls:[{IncomingUrl:"test10",status:"inactive"},/** ...*/]}],"pagesUrl":[{IncomingUrl:"test1",status:"active",pages:"doc1",isDraft:false},{IncomingUrl:"test2",status:"inactive",pages:"doc1",isDraft:false},{IncomingUrl:"test4",status:"active",pages:"doc2",isDraft:false},{IncomingUrl:"test10",status:"inactive",pages:"doc2",isDraft:false}]}

db.pagesUrl.aggregate([{"$match":{/** ...*/IncomingUrl:{$in:["test1","test2","test3","test4"]}}},{"$group":{"_id":null,"response":{"$addToSet":"$IncomingUrl"}}}])