To import from Moodle you will need to create a new group through the "Add Group" page. You will also need to know the Moodle server address and the Moodle service token. Once, you enter a name for the group, click on the "Third-Party Integration" tab an choose "Moodle" from the "Import Type" dropdown menu.
This is the domain where your Moodle server resides.
Moodle Service Token
This is the service token provided by Moodle for web services. Reference your Moodle documentation on how to retrieve this token and enable web services.
Once you enter the server address and service token in the fields provided, click on the "Test Configuration" button. When the system verifies the connection, the number of users found will be displayed in the "Group Targets" section. At this point, you can click "Create Group."
To re-sync the group later, you will need to click on the link icon on the "Manage Groups" page next to the name of the group.