How to jump node in WWF flowchart dynamically?

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WWF

For some reason, I need to change flowchart route on runtime.

For example, there's a flowchart which route is:

A -> B ->C -> D

then, we started the workflow and it current on stage C.

A -> B ->C -> D

and now, we want the workflow go back to A or B, but there is no route line from C to A or B. Can we force workflow to jump to A or B programmatically?

A -> B ->C -> D
or
A -> B ->C -> D

Thanks!