The destination is decided before the task sequence is created and dispatched (Send to Port -> Use Transport).
While you can decide which TE moves the item depending on the port, this might lead to situation where one TE stays idle because all remaining items are headed to the other queue.
2connection_1.fsm
By using a list and Process Flow, you can first assign a TE to the item and this then determines the destination. Meaning the availability of the TEs determines the destination.
2connection_2.fsm
(Technically you can also change the destination after a TE starts the task sequence. But that requires some more advanced knowledge of Task Sequences and coding in FlexSim.)