jBPM Web Designer focuses on BPMN2 nodes that are supported by the jBPM runtime. Collaborations are currentrly not yet executable by the runtime and are not included in Designer. You could model such business process using the new Eclipse Modeller however it would not be an executable process.
You can still have multiple swimlanes in your process, thats no problem, however currently a single pool is supported by the runtime (which is the canvas/drawing area in Designer).
I'm pretty sure with that you will be able still to model (and execute) your business requirements. If you have an example of what you are trying to do let us know.
Thanks for your information.
I fully understand that jBPM Web Designer just focus on an executable BPMN2 process model at level 3. And I also think such collaboration diagram is not needed at level 3.
Level 3 diagram only shows activties that the process engine cares.
However, collaboration diagram is used in Level 2 process modelling which is mainly for showing operational details and coordination details. I think Collaboration diagram is very useful for documentation and communication purpose. It's more for business users.
I can use Eclipse modeller for the time being, but I found jBPM Web Designer is just much easier to use compared to Eclipse one and have very good integration with Guvnor.
Focus is on being able to create executable business processes in the jBPM runtime and we already have and continue to add in many useful features for business users around that, such as process and task form editors, guided property editors, process simulation, visual validations etc etc.
Currently we are not planning to add collaboration in the near future, however community contributions/help would speed it up.