2026 Week 25 | Power BI: Find the difference from a selected value

Introduction

We have a new contributor to WoW for Power BI, Robbin Vernooij.  Please check out Robbin’s challenge below, including the solution video! ⬇️

This week we’re looking to give our users the capability to select which sub-category they want to use as a comparison value for all others!

This technique has many different use cases, and in this challenge we are using it to make diverging bar charts.

We have two separate challenges in one: the first trying to solve the challenge of returning a user selected value and an additional one with multiple stages of formatting and a bit more DAX required.

Dataset

Requirements

Connect to the data from GitHub.

Left chart:

  1. Create a slicer that allows the user to select a Sub-Category.
  2. Return the value of the selected subcategory and subtract it from the total sales (sum of sales) in order to create the diverging bar chart.
  3. Add data labels showing + if above and – if below the selected value, don’t display the label if the difference is 0.
  4. Return the selected Sub-Category in the subtitle of the bar chart.

Right Chart:

  1. Create a slicer that allows the user to select a Sub-Category. Use radio buttons and make it single-select.
  2. Return the value of the selected subcategory and subtract it from the total sales (sum of sales) in order to create the diverging bar chart. (Same as the left chart.)
  3. Add data labels showing + if above and – if below the selected value, don’t display the label if the difference is 0. (Same as the left chart)
  4. Use the slicer values as your y-axis categorical values for the bar chart.
  5. Add tooltips that use the new sentence formatting

Hints:

  • It uses a button slicer.
  • Selecting “No Comparison” returns the total sales.

Share

After you finish your workout, share on BlueSky or LinkedIn using the hashtags #WOW2026 and #PowerBI, and tag @MMarie, @shan_gsd, @KerryKolosko (on BlueSky). Tag Robbin Vernooij on Linkedin. 

Solution