Need Drill-Down Functionality in Waterfall Chart Using Field Parameters and Hierarchy

Hi,

I’m working on a Waterfall visual in Power BI where I’m comparing Budget vs Actuals for different hierarchical levels (e.g., Category → Subcategory → Product → Item).

What I Have Set Up:

I’ve created a Steps table to control Budget and Actuals:

WaterfallSteps =
DATATABLE(
"Step", STRING,
{
{ "Budget" },
{ "Actuals" }
}
)

I also created a Field Parameter to control which hierarchy level is shown in the Category section:

CategoryHierarchyParameter = {
("Category", NAMEOF('Fact_Sales'[Category]), 0),
("Subcategory", NAMEOF('Fact_Sales'[Subcategory]), 1),
("Product Group", NAMEOF('Fact_Sales'[Product_Group]), 2),
("Item Name", NAMEOF('Fact_Sales'[Item_Name]), 3)
}

And I’m using the following measure for my Y-axis values:

MTD_Value =
SWITCH(
TRUE(),
SELECTEDVALUE(WaterfallSteps[Step]) = "Budget", [MTD_Budget],
SELECTEDVALUE(WaterfallSteps[Step]) = "Actuals", [MTD_Actuals],
-- For other cases, show variance
NOT ISBLANK(SELECTEDVALUE('Fact_Sales'[Category])), [MTD_Variance]
)

Current Visual Setup:

• Category: CategoryHierarchyParameter

• Breakdown: WaterfallSteps[Step]

• Y-axis (Values): MTD_Value

The chart works as expected at the first level (for example, showing Budget and Actual bars for each Category).

My Requirement:

When I click on a particular Category, I want to drill down to the next level (for example, Category → Subcategory → Product Group → Item) within the same Waterfall visual — similar to how drill-down works in a Bar or Column chart.

However, currently, the Waterfall visual only shows one level from the field parameter and doesn’t support drill-down to the next level.

My Question:

Is there any way to enable drill-down functionality in a Power BI Waterfall chart that uses field parameters for hierarchy selection?

Example Expected Behavior:

1. Initially see “Category ” level → bars show Budget vs Actuals.

2. When clicking on one Category → show related “Subcategory” details.

3. Drill again → show “Product Group,” and so on.