如何在Highcharts中使用分组类别时检索父类别？

I am using the grouped categories library here https://github.com/blacklabel/grouped_categories. How would I retrieve a parent category? For example, how would I get/return the category "Fruit" from the graph here: http://blacklabel.github.io/grouped_categories/. I have tried this.x which returns both the parent and subcategories of a point. this.category.name would return the subcategory, or "Apple" in the example.

You almost got it. Talking about tooltip, you can reach parent category name with this.x.parent.name. Looks like that you can get any parent level this way;

Try it: jsFiddle