13.9. Chart Dimension Drill Down

Chart drill down is an interaction that allows users to explore data at different levels of granularity by drilling up and down between dimensions in a hierarchy. This feature is particularly useful when you want to provide the viewer with the ability to explore data at different levels of detail.

Hierarchy in Dimensions

To implement a drill down effectively, there should be a hierarchy within the dimensions. Some common examples include:

Dates: Year, Quarter, Month, and Day
Geographical: Continent, Country, Region/State, and City

Let's explore these hierarchies with a time series chart.

Enabling Chart Drill Down

To enable chart drill down in Data Studio:

Click on the chart for which you want to enable drill down.
Under the chart's settings, enable "Drill Down".
Add the desired dimensions in the hierarchy (e.g., year, quarter, month, day) to the list of drill-down levels. The order matters, as it determines the drill-down order.

Once enabled, an icon will appear in the chart header. Users can click on this icon to drill down through the hierarchy.

Time Series Chart Drill Down

Imagine a time series chart displaying the number of new users over four years. The dimensions in the drill down are set in a specific order: Year, Quarter, Month, and Date. The user can then click through each level of granularity to see the data at different levels. For example, they can drill down from Year to Quarter, then from Quarter to Month, and finally from Month to Day.

Note that if you disable the drill down feature, you'll need to recreate the dimensions.

To help users understand the functionality, consider adding a title or guidance text near the chart. For instance, you could add "Use the arrows to drill down for different date range granularities."

Table Drill Down

The same concept applies to tables. Imagine a table displaying data on continents, countries, and cities. If you drill down from Continent to Country, you'll see one row per country across all continents. However, if you first select a specific continent and then drill down, you'll only see countries within that selected continent. This can be done on subsequent levels as well, such as selecting a country and drilling down to view its cities.

Drill Down vs. Cross Filtering

It's essential to distinguish between drill down and cross filtering. Drill down allows users to explore data at different levels of granularity without affecting other charts on the canvas. Cross filtering, on the other hand, filters the data on one chart based on the selected data on another chart, impacting all related charts on the canvas.

By allowing users to drill down through dimensions in a hierarchy, you provide them with the flexibility to analyze data at various granularities. This feature, when combined with optional metrics and metric sliders, can create highly customizable and interactive reports.