Yes - students can be in multiple groups.
- Click manage students
- Click groups
- Use the find student search box to search for your student. Remember to click go
- Drag their name into a group. Their name will stay on the left side of the page so that you can drag them into multiple groups.
You can also use the select students option on the roster to select multiple students and put them into multiple groups. Read more about how to add students here.