A single Netprobe can connect to multiple Queue Managers as long as its samplers are using the Mq server connection setting.
Note: there had been a user reported error code RC2103 MQRC_ANOTHER_Q_MGR_CONNECTED when trying this configuration. However, this happened long time ago in year 2015. If you encounter similar error, please make sure the Netprobe and MQ Client versions are up-to-date.
Please refer to the MQ Queue plugin documentation (connection > mqServer option).