When teachers record an activity for their entire class, they can filter based on student schedules so the activity applies to the correct students.
To do this in the Teacher app, tap the New Post button, select the activity, and tap "Next," then tap the "Schedule" drop-down option above "Quick Add," select the correct filter option, and tap "Done."
Select your students/staff and tap "Next" in the upper-right hand corner to create your post and click "Post" when finished.
*Please note that students must already have schedules created to use this filter option.