Drilldown into the Content of a Line Chart

It would be great if you could drill down in a line chart based on the content in the line chart, not the date.

For example, let's say cookies, pies, and gelato are a subset of desserts. I create a line chart that shows the average profit for desserts for each month for the last six months. I then want to drill down into the specific desserts that I offer, so it would jump from one line (desserts average profit) to three lines (average profit for cookies, pies, and gelato). The x-axis and y-axis stay the same, but I'm able to see a new level of detail in the content of the chart.

This would also be useful for bar charts where the x-axis is the date, for example. The x-axis and y-axis stay the same, but you're able to drill down into the hierarchy to look at the sub groups that make up each bar.