To enable MySQL replication operations to act on individual
      replication channels, use the FOR CHANNEL
       clause with the
      following replication statements:
channel
      The SOURCE_POS_WAIT() function has
      a channel parameter.
    
      START REPLICA and
      STOP REPLICAare disallowed for the
      group_replication_recovery and
      group_replication_applier channels.
      SHOW REPLICA STATUS is also not
      allowed with the group_replication_applier
      channel.
    
      FLUSH RELAY LOGS
      is allowed for the group_replication_applier
      channel, but if the request is received while a transaction is
      being applied, the request is not performed until after the
      transaction ends. The requester must wait while the transaction is
      completed and the rotation takes place. This prevents transactions
      from being split, which is not allowed for Group Replication.