A tracker group is helpful when you would like to compare different hashtag trackers against each other.
Here is a short video:
'Edit' is for you to add or remove a certain hashtag tracker from the tracker group. You can also edit the title and colour of the tracker group here.
'Delete' is for you to delete the group. This will not delete your tracker.
'Compare Groups' is for you to compare the groups if you have more than one tracker group.
Also, you will be able to see the hashtag trackers being tagged:
Note: The same tracker can be added to different groups.