Determine what buttons are in CCSM?

It shows 20 buttons by default, which doesn't mean you actually can trigger 20 buttons.

To check which ones work, you can use the xev command. Type the command into a terminal, ensure the xev window has focus and then try your buttons:

Button numbers are shown as highlighted.

On touch pad,

Single tap             - Button1 (left click)
Two finger tap         - Button 3 (right click)
Two finger up swipe    - Button 4 (scroll)
Two finger down swipe  - Button 5(Scroll)
Two finger right swipe - Button 7(Horiz. scroll)
Two finger left swipe  - Button 6(Horiz. scroll)

I find xinput a little more convenient than xev:

xinput test n

where n is your mouse's device number. To find that number, use

xinput list