Drill-down
Drill-down moves within one visual, down a hierarchy. Add several fields to the axis in order — Year, Quarter, Month — and the visual gains drill controls in its header.
The four buttons matter and confuse people:
| Control | Does |
|---|---|
| Down arrow | Enables click-to-drill on a data point |
| Double arrow | Expands all to the next level at once |
| Split arrow | Expands the next level while keeping the current one |
| Up arrow | Back up |
Drill-through
Drill-through moves to another page, carrying the selected context.
Create a detail page, then drag a field into the Drill through well in the Visualizations pane. Right-clicking a data point elsewhere in the report now offers to drill through to that page, filtered to the value clicked.
Power BI adds a back button automatically. The typical shape is a clean summary page with detail pages behind it, rather than one dense page trying to serve everyone.
Keep all filters
The Keep all filters toggle on the drill-through field controls whether the source page's other filters travel with the selection.
On is usually right — drilling from a page filtered to 2024 should give 2024 detail. Off gives you only the drilled value, across all time, which surprises people.
Cross-report drill-through
Enabled in report settings, drill-through can target a page in a different report in the same workspace.
Useful for a summary report drilling into a detailed operational one, though it depends on both reports and their filters staying compatible — a fragility worth weighing.