Ravindra BagaleCourses & study guides

21. Dynamic Charts: Field Parameters, What-if and Dynamic Top N

21.5 Dynamic Top N with a Parameter

The Filters pane Top N (Module 22.4) uses a fixed N. To let users choose N with a slider:

Steps in Power BI

  1. Modeling › New parameter › Numeric range › Name Top N, Whole number, 1 to 20, increment 1, default 5 › Create.
  2. Create the measure below.
  3. Bar chart: Y-axis = Product Name, X-axis = [Top N Sales]. Products outside the top N return BLANK and disappear from the chart.
  4. Sort by Top N Sales descending. Add a dynamic title "Top " & [Top N Value] & " products by sales".
Top N Value = SELECTEDVALUE('Top N'[Top N], 5)

Top N Sales =
VAR n    = [Top N Value]
VAR rnk  = RANKX(ALLSELECTED(Product[Product Name]), [Total Sales], , DESC, Dense)
RETURN IF(HASONEVALUE(Product[Product Name]) && rnk <= n, [Total Sales])

Because of ALLSELECTED, the ranking respects slicers. For example, the top 5 in Nagpur on Amazon Now.

Ties

With Dense ranking, two products with equal sales share a rank, so you may see more than N bars. That is correct. Explain it in the subtitle, or add a tie-breaker.

Dynamic Top N interview madhe scenario mhanun khup yeto. Ha measure swatah lihun bagha.

Ravindra Bagale's Tip

Friends, many students build Top N with RANKX but forget ties, so "Top 5" shows 6 products. Decide how ties should behave (show them, or break them with a second measure), and tell users what happens. Test with a City filter to make sure the ranking respects slicers. Practise, and it will feel very easy.