Dynamic label display on charts

Ability to hover over a line on a chart and see which member of the hierarchy the data point is showing. Currently, we only see the data value on the line with the label on the sides. However, when handling a chart with a multitude of lines, it helps to be able to hover over the line for a quick display.

Example, line graph with 20 cost centers and 20 labels on the horizontal axis. There's one line with the highest jump in spend over the course of a year. Currently, we need to match the colors, which can be very similar when using a graph with many lines.