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".