[{"title":"one title","articles":[{content:"lorem ipsum",authorIds:[1],},{content:"bacon ipsum",authorIds:[2,3,4]},{content:"hippsum dippsum",authorIds:[3,5]},{content:"hippsum dippsum",authorIds:[4]}],}]

db.collection.aggregate([{"$project":{title:1,articles:1,articleCount:{$size:"$articles"},},},{"$redact":{"$cond":{"if":{"$or":[{"$eq":["$authorIds",2]},{$gte:["$articleCount",1]},]},"then":"$$DESCEND","else":"$$PRUNE"}}},])