I assume that you have created two sliders called sdr1 and sdr2 e.g.

GHorzSlider sdr1;
GHorzSlider sdr2;

Then to separate the sliders events we do

void handleSliderEvents(GSlider slider){
      if(slider == sdr1){
            maxWeight = slider.getValue();
      }
      if(slider == sdr2){
            maxTrans = slider.getValue();
      }
}