it is actually up to you to define multi tenancy when building systems that embed jBPM. For future versions of kie wb there will be some support of multi tenancy capabilities, like each kjar can be deployed with various settings like independent data source, persistence config, etc. API already allows it so you should be able to configure it according to your requirements.
But, how can we manage process definitions differently for each group of users. Say, we have two group of users. So, how can we manage some process definitions for one group and some other process definition for other group.
And, how can we categories the process instances for a particular user group. like, this process instance belongs to which user group?
in version 6.1 there will support of roles based deployments so only user with proper roles will be able to start and work on processes.
An implementation of jBPM, which is an integration product, involving - organisation structure, participating systems(Apps), persistence database, etc.
An organisation using jBPM needs to focus on URI, target name space, authentication system(organisation Structure).
So resulting implementation derives the possibility of multi-tenant system.
I wish to get updates to my view.