[{"name":"abc","age":30},{"name":"acb","age":45},{"name":"dba","age":32},{"name":"abgt","age":30},{"name":"abab","age":30},{"name":"acab","age":30}]

db.collection.find({$expr:{$and:[{$gt:["$age",10]},{$regexMatch:{input:"$name",regex:"ab"}}]}})