Section 5.1.3 of the Usxer's Guide seems to have the dynamic process creation covered.
http://docs.jboss.org/jbpm/v5.2/userguide/ch05.html#d0e783
There is not a "template" construct as such, however, there are reusable sub-processes.
http://docs.jboss.org/jbpm/v5.2/userguide/ch05.html#d0e1303