1: jbpm can do everything you can do in plain java.
2: you can't directly do this at the moment. If you build your own ui, you can filter them out
Thanks for your reply.
About Reply 2-could you please share some knowledge docs? As I am relatively new to Jboss ,have no idea about how to build own User Interface in jboss jbpm.
you just build a jsf userinterface and from backingbeans access the jbpm api. So you do not build a ui IN jbpm....