The Solution is the range option. You'll have to make an object with the values for the postion on the slider, the value at that postion and the distance to the next value.
var rangers = {}
for (i = 0; i < filterLength.length; ++i) {
var prozent = Math.ceil((100/filterLength.length) * i)
if ( i < filterLength.length-1 ) { rangers[prozent+'%'] = [ filterLength[i], filterLength[i+1] - filterLength[i] ] }
if ( i == filterLength.length-1 ) { rangers['max'] = [filterLength[filterLength.length-1]]; }
}
$("#slider-length").noUiSlider({
start: [ filterLength[0], filterLength[filterLength.length-1] ],
range: rangers
});