In the Australian design there’s generally an arrow indicating which direction it goes. It’s embossed to for vision impaired people to be able to feel it too (it also is designed to resonate so if you touch it, you can feel the audio signals so if there are two directions, a vision impaired person knows which direction the sound is saying is safe to cross without needing to see the light signals).

As well as the arrows, the buttons are just positioned intuitively most of the time. We usually get two perpendicular kerb ramps rather than a diagonal one pointing at the centre of the intersection. The button for the crossing you want is the one closest to you or facing you when you're waiting at the intended ramp.

The button gets mounted on its own post if there's not a traffic light pole in the right place to piggyback off.