Hi,
In general, personally I think that to get that information you should query history tables instead of execution. That will give you quite good set of information about your process instance execution path.
I think that jBPM saves information for all activity types in history. To illustrate this please take a look at attached screen shots of a bit modified BPM console and a process. Here I used following activity types:
- java
- state
- decision
HTH
Maciej