您需要准备对sublabel进行分类的数据集。
每个数据集应包含x轴类别长度（label）的值，即3。

let labels = [...new Set(data.map((x) => x.label))];
let subLabels = [...new Set(data.map((x) => x.sublabel))];
let subLabelDatasets = subLabels.map((x) => {
  let datasets = [];

  for (let label of labels) {
    datasets.push(
      data.find((y) => y.label == label && y.sublabel == x)?.count || 0
    );
  }

  return {
    label: x,
    data: datasets,
  };
});

this.barChartLabels = labels;
this.barChartData = subLabelDatasets;

字符串
Demo @ StackBlitz
subLabelDatasets可以简化为：

let subLabelDatasets = subLabels.map((x) => ({
  label: x,
  data: labels.map(
    (label) =>
      data.find((y) => y.label == label && y.sublabel == x)?.count || 0
  )
}));

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