multi threading while using tMOMInput in keep listening mode

[BipinNS]

simplified scenario:

have a job that is listening to MQ using tmominput in keep listening mode. For every incoming message, needed data is extracted from the incoming message and passed on to a subjob for further processing.

limitation here is, it can only pick one message from the queue at a time, and until and unless the processing is completed only then the job can pick another message.

What is needed:

need to be able to pick multiple messages lets say 4 messages at a time and process these 4 messages in parallel - multi threading.
But still need to keep using keep listening mode. Also if we could control how many thread to use dynamically.

I've tried few options, like using multi threading that comes with iteration, batching option with main connector,etc but non of them works, when using tmominput with keep listening. 

Any suggesions would be highly appreciated.