Multi Master - Master Replication mysql
While technically this is possible, as MySQL 5.7 supports multisource replication, so one instance can replicate from 2 other servers, it is unlikely you want to setup that.

Regular replication does not resolve write conflicts, so those would have to be solved at application layer or it would only serve work for trivial configurations (e.g. each server working with a separate database or just doing appends to a table).

If you want a proper MySQL cluster with multi-masters and conflict resolution, check Galera/Percona XtraDB Cluster, InnoDB Cluster or NDB Cluster.