[{"name":"somename","level":"123","nested":[{"somefield":"test3","file":{level:"123"}},{"somefield":"test2","file":{level:"124"}},{"somefield":"test","file":{level:"123"}}]}]

db.collection.aggregate([{$unwind:"$nested"},{$match:{$expr:{$eq:["$nested.file.level","$level"]}}},{$set:{min:{$let:{vars:{index:{$indexOfArray:[["test","test2","test3","test4","test5"],"$nested.somefield"]}},in:{$cond:{if:{$gt:["$$index",-1]},then:"$$index",else:100}}}}}},{$sort:{min:1}},{$limit:1},{$group:{_id:"$_id",setting:{$first:{$cond:{if:{$lte:["$min",4]},then:"$nested",else:"Did not match"}}}}}])