What is the ruling regarding the remaining things sworn upon in a single oath, after breaking one of them and offering expiation? Do they remain under the ruling of the original oath, or has the oath been dissolved by offering the expiation?

If the oaths concern multiple things with a single oath, then performing some of what was sworn upon breaks the entire oath, and one expiation is sufficient for all of them. However, if there are multiple oaths for each action, then each action requires a separate expiation.