My brake lights are out, but the third brake light in the rear window works ? what could be the problem on my 2002 toyota camry

SOURCE: 2002 Toyota Camry no brake

You've checked the obvious items and the fact that the high level lamp works proves that the brake lights switch works.

That means it must be a wiring fault, most likely a connector which has come apart (partially or fully) or which has corrosion on the terminals.

Look at the brake switch which is mounted just above the brake pedal and identify the wiring colour.

Now take panels off inside the boot (US= trunk) and identify the same colour/pattern wire. As you trace it, one junction will send a feed to the third light, the other will feed the remaining two lights. Undo the connector, check for corrosion (anything other than bright metal is corrosion, if you see corrosion clean it off back to bright metal) and refasten it together. Check the brake lamps.
If not working trace the wire all the way to each lamp and check for other connectors and give them the same treatment.

If all that is fruitless, then check for a single wire which leaves each cluster and goes to a screw or bolt directly into the vehicle body. This will be the earth return (US = ground return) part of the circuit. Undo the connection to the body and clean off any corrosion back to clean bright metal. It's unlikely to be the earth return though, as the indicators (US= turn signal lights also wouldn't be working as the return is common to both circuits.