In order to define which collection of groups you wish to use with a Moodle activity, you need to create a Grouping.
To use the Grouping in an activity, first go to the ‘Settings’ page of your Moodle activity.
For Moodle Assignment with Group submissions (click for extra step)
If the activity is a Moodle Assignment for which the students will be submitting in groups, please follow this additional step.
Locate the ‘Group submission settings’ section and for ‘Grouping for student groups’, select the name of the ‘Grouping’ (to which the groups for submission belong):
For all activities, you need to configure the Group mode and Grouping settings in the ‘Common module settings’ section.
Scroll down to the ‘Common Module Settings’ section and select the ‘Group mode’ as Separate Groups.
Visible Groups is also available, but this is only used if you want the participants of a group to be able to view the work of other group(s).
For ‘Grouping’, select the name of the Grouping that you have previously defined (and to which the groups you wish to engage with this activity belong):
Scroll to the bottom of the ‘Settings’ page and click on Save and return to course to confirm your changes.