When creating the event from the calendar, if you select the "More Options" button, you can choose to "Use a different date for each section". While that doesn't seem to be mentioned (as far as I could find), from a quick experiment, you can leave dates blank for some sections.

For more detailed instructions with images, see How do I set a different event date for each secti... - Instructure Community - 617603

Alternatively, you can make an Assignment with a due date and assign it to just some sections. That should also only show up in those section's calendars.