You can easily move between groups, from within each group's details page, instead of returning to the Group's list page every time.
1. Go to the desired Competition, and click on the Performances Tab.
2. From the Performances Groups list, click View to any of the groups
3. From within the Group's details page, click the drop-down menu from the right top corner
4. Select the group you would like to switch to from the available list
Note: Performances Groups need to be enabled via the Competition settings for this function to be available.