Step 1, click "Turn on editing".

Step 2, click  "Add an activity or resource".


Step 3, choose "Lesson" from the activities.


Step 4, give it a name and required description.


Step 5, now this is a result.

Add Clusters

Step 1, click "Add a cluster".


Step 2,  choose "Add a cluster".

Step 3, click on the button "Setting".


Step 4, a jump you can choose "cluster" and click "Save page".


Step 5, now you can see the jump is "Cluster".