Covered with automated tests.   For manual test: Create a course with at least two sections. Go to the course and create different activities in different sections with completion enabled. Enrol at least one student on the course. Go to "Course administration" -> "Reports" -> "Activity completion" Check you see a dropdown "Activity section" with the option "Do not filter by section" enabled. The table below should show all activities of the course that have activity completion enabled. If you choose a section in the dropdown, the page should automatically refresh and show only the activities of the corresponding section.