Guide or app designer?
The slider property 'Value' determines the position of the slider bar. The value must be between the slider limits.
To move the slider when the pushbutton is pressed, the pushbutton callback function needs to change the value property of the slider. Add to the current value to move it forward. Subtract from it to move backward.
In guide, the code for the forward button might include something like this (untested)
sVal = get(handles.slider1,'Value');
set(handles.slider1,'Value',sVal+2);
In app designer, it might include this
app.slider1.Value = app.slider1.Value + 2;
Of course you'll want to include a check that only adjusts the value if the result is within the slider limits. You'll also want to set the amount you change Value to meet your needs.
