button becomes available only upon selecting published flight or a number of flights from one pairing.
Once you selected the flight(s) and clicked on the button, you will be transferred to OPS > TABLE view, and the pairing will be edited.
It is also possible to move back from the OPS view to SCHED as long as the flight selected in OPS views was added in SCHED.
Simply select the flight originally added in SCHED. button will appear. Clicking on it will transfer you to SCHED view, where the flight will be selected. This will happen for flights with either virtual or non-virtual aircraft assigned.