There are three buttons on the left side of the driver seat on the bottom of the dashboard beside the steering wheel. l know that the 3rd one closest to the steering wheel is for the fog lights but l do not know what the other two do.
l actually have 3 buttons there but l do not have the manual with the car because l bought it used.

Do you have 3 buttons or 3 slots for buttons? l know on my 02, the fog light button was there and the button to turn on the cruise control was there. On some models, there is a headlight leveling switch there too. If anything, look in the manual and it should tell you what they are for. If you do not have a manual, you need to get one because the maintenance schedule is in there and you need to follow that too.

One is the self destruct button and the other is the seat ejection button.

The 3 buttons.

One is for your foglight, one is for cruise control (if you equipped), one is the security (if you equipped with the OEM style alarm). The other extra one is the security light flasher.

So there should be 4 slots. Most the OEM vehicle without option(s), cruise control, fog lights, and security, will only have one filled.

The picture showed a sample of a Impreza Wagon, that is Outback sport.