To create a custom waterfall chart with subtotal categories in Power BI, perform the following steps:
1. Restructure Data into Custom Subtotals
For the Waterfall breakdown, Power BI requires a Category column.
To achieve this, you will need to modify your dataset through either Power Query or DAX and create rows to suit your custom subtotals.
Sample Table Format:
Step        | Value  | Type  
------------|-------|---------  
Sales       | 5000  | Increase  
Costs       | -2000 | Decrease  
Profit      | 3000  | Subtotal  
Taxes       | -500  | Decrease  
Net Profit  | 2500  | Subtotal  
2. Use DAX to Create Custom Subtotals
- If subtotals are calculated dynamically, create a DAX measure:
CustomSubtotal =  
IF(  
    SELECTEDVALUE(WaterfallTable[Step]) IN {"Profit", "Net Profit"},  
    SUMX(FILTER(WaterfallTable, WaterfallTable[Step] <> "Profit" && WaterfallTable[Step] <> "Net Profit"), WaterfallTable[Value]),  
    SUM(WaterfallTable[Value])  
)
3. Setup the Waterfall Chart in Power BI
Set Category as the x-axis and Value as the y-axis.
Ensure that "Profit" and "Net Profit" are both classified as Total in the settings of the Waterfall Chart.