BRMS Rule. Complex Object Usage in Rules

Hello,

Is there a way to use complex objects, defined in the data modeler, in the "when" and "then" clauses of a rule?
When we try to define a rule with a "when" clause like this "when aClass.bClass.cClass == someValue" and we save it, the behaviour is not what we expect. Some "not bound" expressions appear in the UI of the clause.
Also when we try to set the value of a complex object in the "when" clause, the option doesn't appear. We can't do aClass.bClass.cClass = someValue. It's only possible to set the value of aClass (aClass=someValue).

Thanks in advance

Daniel.