display tooltip for group bar chartjs code example

Example: display tooltip for group bar chartjs

tooltips: {
   mode: 'label',
   callbacks: {
      label: function(t, d) {
         var dstLabel = d.datasets[t.datasetIndex].label;
         var yLabel = t.yLabel;
         return dstLabel + ': ' + yLabel + ' €';
      }
   }
}