Interactive visual calculations in Power BI

Comparing performance across any dimension can be messy, as if you're not careful you'll require multiple visuals (one for each element of the dimension table whose values you're comparing). In this blog we will let our end user decide for which year to compare sales:

Check if this is the effect you want by clicking here to try the report.

The first thing to do is create a table with a unique list of the values you are interested in. This can be a static table (for which you type in data) or a live connection:

This example is using a query to the same source as my data, but with the duplicates and extra columns removed. I've called the table Live Slicer table.

If you try to use the same model table or column for the slicer as for the data in the visual then the visual will be filtered (which we don't want)! Your data model should thus include a disconnected slicer table, like this:

The Purchase table contains all of the sales data, while the Calendar table splits the dates into Year, Month etc.  Notice that the slicer table is separate: it doesn't directly filter anything.

Now to create a slicer with the column from the Live slicer table table (and a visual with the same column from the data table):

The results aren't very exciting without a measure to tie the visuals together!

Now create a measure to calculate the total sales for the column year, but subtracting the selected year's sales:

Adding this measure to the visual gives the desired effect:

All that is left to do is change the titles - and perhaps add some conditional formatting.

The title measure works using the same idea as the calculation above. Use VALUES to return the only year that is left:

This can be applied by turning the Title property to ON and then hovering to the right of the text box and clicking the dots that appear.

Choose the measure Chart Title as the Title text field.