You are designing a complex report that displays sales metrics for a customer hierarchy. The customer hierarchy has six levels and contains approximately 1 million members. You have the following…

Retrieving all 1 million customers in a single query and using drilldown groupings to hide rows still loads the entire dataset into memory, significantly increasing processing time and violating the performance requirement.

Adding a separate report part for each of the six hierarchy levels increases design complexity and maintenance effort, violating the requirement to simplify the report design and maintenance processes.

Using a subreport for each hierarchy level causes separate server-side processing requests per level, introducing significant performance overhead and increasing design and maintenance complexity.

Displaying only the children of the current hierarchy level and using drill-through to navigate deeper loads data on demand in small, focused queries rather than retrieving all 1 million members at once, directly minimizing report processing time. A single parameterized report handles all six levels without requiring separate components, which simplifies both the design and ongoing maintenance. This pattern also improves the user navigation experience by presenting manageable subsets of data at each level.