How to create a search on followers?


I am creating an App and I have successfully implemented the user login part and able to retrieve the users followers.
But I don’t want to get all the users.
I want to send a direct message to a follower such that i can create a search on followers and get the list according to the search and select one of them.

I’m looking for a way to get a create a search filter on the followers. How can it be done?