You can use DSCC to perform this task. For information, see Directory Service Control Center Interface and the DSCC online help.
If you also have multimaster replication, ensure that one master has the complete set of data to replicate, then use this master to initialize the replica on each of the other masters.
Initialize the replicas on the first-level hub replicas from their master replicas.
If you have several levels of hubs, initialize each level from the previously initialized level of hubs.
From the last level of hub replicas, initialize the replicas on the dedicated consumers.