(function( $ ){
 
  $.fn.sliderButtons = function(options) {
 
    // The defaults, extended and modified with any passed in the function call
    var opts = $.extend( {
    downText: '-',    // Text for the "down" button
    upText: '+',    // Text for the "up" button
    scrolling: true,  // Continuous slider movement if left mouse button held down
    scrollInterval: 150,// Interval (in ms) between slider movement when button is held down
    valuePrefix: '',  // Prefix for callout
    valueSuffix: ''  // Suffix for callout
    }, options);
 
    return this.each(function(i) {
 
      var thisQuestion = $(this);
 
      // Add some classes
      $(thisQuestion).addClass('slider-button-question');    
 
      // Insert the buttons
      $('.question-item', thisQuestion).append('<div class="clearfix" />\
                            <div class="slider-button-wrapper">\
                              <button type="button" class="slider-button down btn btn-md  btn-primary">'+opts.downText+'</button>\
                              <button type="button" class="slider-button up btn btn-md  btn-primary">'+opts.upText+'</button>\
                            </div>');      
      // Initial button states
      function handleButtonState(slider) {
        var thisRow = $(slider).closest('.question-item');
        var thisSliderVal = $(slider).val();
        var thisSliderStep = $(slider).attr('data-bs-slider-step');
        var thisSliderMin = $(slider).attr('data-bs-slider-min');
        var thisSliderMax = $(slider).attr('data-bs-slider-max');
        $('button.slider-button', thisRow).prop('disabled', false);
        if (thisSliderVal == thisSliderMin) {
          $('button.slider-button.down', thisRow).prop('disabled', true);
        }
        if (thisSliderVal == thisSliderMax) {
          $('button.slider-button.up', thisRow).prop('disabled', true);
        }
      }
 
      $('input:text.form-control', thisQuestion).each(function(i) {
        var thisInput = $(this);
        $(this).on('slideEnabled', function( event, ui ) {
          var thisRow = $(thisInput).closest('.question-item');
          handleButtonState(thisInput);
          if($('input.text', thisRow).val() != '') {
            $('.tooltip-inner', thisRow).text(opts.valuePrefix+$(thisInput).val()+opts.valueSuffix);
          }
 
          // Listener on sliders
          $(thisInput).on('slide slideStop', function( event, ui ) {
            handleButtonState(thisInput);
          });
        });
      });  
 
      // Function to handle button actions
      function handleButtons(thisButton) {
        var thisRow = $(thisButton).closest('.question-item');
        var thisSlider = $('input:text.form-control:eq(0)', thisRow);
        var thisSliderStep = $(thisSlider).attr('data-bs-slider-step');
        var stepDecimals = 0;
        if(thisSliderStep.toString().indexOf('.') >= 0) {
          stepDecimals = thisSliderStep.toString().split('.')[1].length;
        }
        var thisSliderVal = Number($(thisSlider).val()).toFixed(stepDecimals);
        var thisSliderMin = $(thisSlider).attr('data-bs-slider-min');
        var thisSliderMax = $(thisSlider).attr('data-bs-slider-max');
        console.log(thisSliderVal+':'+thisSliderMax);
        if ($(thisButton).hasClass('down') &amp;&amp; Number(thisSliderVal) > Number(thisSliderMin)) {
          $(thisSlider).bootstrapSlider('setValue', Number(thisSliderVal)-Number(thisSliderStep));
        }
        if ($(thisButton).hasClass('up') &amp;&amp; Number(thisSliderVal) < Number(thisSliderMax)) {
          $(thisSlider).bootstrapSlider('setValue', Number(thisSliderVal)+Number(thisSliderStep));
        }
        var newValue = Number($(thisSlider).val()).toFixed(stepDecimals).replace(/\./, LSvar.sLEMradix);
        var hiddenInput = $('input.em_sq_validation:eq(0)', thisRow);
        $(hiddenInput).val(newValue).trigger('change');
        $('.tooltip-inner', thisRow).text(opts.valuePrefix+newValue+opts.valueSuffix);
      }
 
      // Scrolling
      if(opts.scrolling == true) {
 
        var sliderTimeout;
        var clicker = $('button.slider-button', thisQuestion);
        var count = 0;
 
        $('button.slider-button', thisQuestion).on('mousedown touchstart', function(){
          var thisButton = $(this);
          sliderTimeout = setInterval(function(){
            handleButtons(thisButton);
          }, opts.scrollInterval);        
          return false;
        });        
 
        $(document).on('mouseup touchend', function(){
          clearInterval(sliderTimeout);
          return false;
        });
        $('button.slider-button', thisQuestion).mouseout(function(){
          handleButtonState($(this).closest('.question-item').find('input:text.form-control'));
        });
      }
 
      // Listener on the buttons
      $('button.slider-button', thisQuestion).on('click touchend', function(e) {
        handleButtons(this)  ;    
        handleButtonState($(this).closest('.question-item').find('input:text.form-control:eq(0)'));
      });
 
      // Listener on reset buttons
      $('.slider-reset', thisQuestion).on( "click", function( event, ui ) {
        var thisReset = $(this);
        setTimeout(function() {
          handleButtonState($(thisReset).closest('.question-item').find('input:text.form-control:eq(0)'));
        }, 150);
      });
    });
  };
})( jQuery );

  .slider-button-question .slider-container {
    margin-bottom: 0;
  }
 
  .slider-button-question .slider-button-wrapper {
    margin: 0 0 0 25px;
    text-align: center;
  }
 
  .slider-button-question .slider-button-wrapper button {
    padding: 0 10px;
    margin: 0 0 0 5px;
  }
 
  .slider-button-question .slider-button-wrapper button:disabled {
    opacity:0.65;
    filter:alpha(opacity=65);
    cursor: default;
  }
 
  .slider-button-question .slider-reset {
    margin-top: 42px;
  }

<script type="text/javascript" charset="utf-8">  
  $(document).ready(function(){
    $('#question{QID}').sliderButtons({
      downText: 'Down', // Text for the "down" button
      upText: 'Up', // Text for the "up" button
      scrolling: true, // Continuous slider movement if left mouse button held down
      scrollInterval: 250, // Interval (in ms) between slider movement when button is held down
      valueSuffix: "%"  // Suffix for callout
    });
  });  
</script>