1. Turn editing on: 

2. Scroll to the bottom of the page and open the extra settings under "Tabs edition utilities." 

3. Under "Move resources between tabs" select "disable." 

Now you will see the arrows next to each activity change from four directions to two. 

4. Click on the activity you would like to move. It will move to the top of the screen above the tabs with a note that says "Moving this activity:" 

5. Select the folder you'd like it to move into. Then click inside the section of dotted lines that you'd like to drop it into.