I know we can set max jobs and flow limit on a TIBCO starter process but is there anyway of explicitly setting it on a sub-process (non starter process)?
Max Jobs and Flow Limit can only be set on process starters or on spawned subprocesses. Flow control on regular (i.e. non-spawned) subprocesses is determined by the parent process starter's configuration and cannot be overridden.
If you want to be able to control the flow of a subprocess, I see 2 options: