A very small but yet so powerful button in Power BI Desktop is the "Enable Drill Down" button.
This button will let you drill down in charts with only a click. Just drag the detail field under the already selected field to create your hierarchy. (In my case (Län - County, Postort - PostalCity)
| Without the drill down function enabled a mouse click will |
instead mark your attribute.
|The button is positioned in the upper right corner of the chart|
|You are now able to drill down in your chart|
You can download Power BI Desktop here: https://powerbi.microsoft.com/en-us/desktop/