Power BI/PowerPivot: Using Slicers to Choose Which Measure to Display

Today, we're going to talk about how to use Slicers to choose which measure you want to display in your Table or Chart.  This is probably one of the coolest and easiest features to implement, yet it completely opens your reporting world.  It easily allows the user to select which measure they want to display, without you having to build multiple tabs or charts.  Let's get to it!

We'll start off by building a very simple data model.

Sales Table

We start with a table of orders.  Each order has a few slicer columns (Date, Month, Category) and a couple of measure columns (Sales, Profit).  We can easily pull this into Power BI Desktop and build some simple charts.

Sales Charts

Now, this is great if we only want to show Sales.  However, what if we want to allow the user to select whether they want to see "Total Sales", "Average Sales", or "Total Profit"?  We can achieve this with a little slight-of-hand.

Create Table

Let's start by creating a table with a single column called Measure.  Remember that slicers/filters can only be creating by using existing columns in your data.  When you select a value in the slicer, it filters the underlying table, as well as any tables further down the chain of relationships.  In our model, we don't have any relationships.  Therefore, when we select a value in the filter, nothing happens.

Unconnected Filter

Now, we need to create a measure that changes based on the value of the filter.  This is where the SWITCH() function comes in handy.  The SWITCH() function is nothing more than a simple way to write long IF-ELSE chains.  In this scenario, we want to check whether [Measure] is "Total Sales", "Average Sales", or "Total Profit" and return the appropriate measure.

Invalid Switch

We get an error.  Since there is no relationship between these two tables, Power BI doesn't know how to choose which of the three values in the [Measure] field to use.  There are a couple of ways to resolve this, and they all depend on how you want the measure to act when multiple values are selected in the filter.  The simplest method is simply to wrap Table2[Measure] in a FIRSTNONBLANK() function.  FIRSTNONBLANK() functions very similarly to MIN().  However, MIN() only accepts numeric data, where FIRSTNONBLANK() can accept any data type.

Selected Measure (FirstNonBlank)

Now, all we have to do is rebuild our charts, replacing [Sales] with [Selected Measure (FirstNonBlank)].

Dynamic Measure (FirstNonBlank) (Average Sales)

Since all of the values are between 7 and 8, we know that are looking at Average Sales.  This is what we would expect given that we have chosen Average Sales in our slicer.  However, what would happen if we selected all values in the slicer?

Dynamic Measure (FirstNonBlank) (No Selection)

We see that the charts still display Average Sales.  This is because Average Sales is the first non-blank value in the Measures column (text fields are sorted alphabetically).  What would the charts look like if we selected the other measures?

Dynamic Measure (FirstNonBlank) (Total Profit)

Dynamic Measure (FirstNonBlank) (Total Sales)

We can see that this methodology works fine when an individual measure is selected, but works somewhat awkwardly when more than one is.  Depending on which media you are using to house your reports (Power Pivot via Excel, Tabular via Excel, Power BI Online, Power BI Desktop, etc.), you may have the option of not allowing the user to select more than option in the slicer.  This would be our preferred option.  However, Power BI Desktop doesn't seem to have that option.  So, let's shoot for the next best thing.

Selected Measure (HasOneValue)

The HASONEVALUE() function will return TRUE if the field contains only one value after all filters are applied and FALSE otherwise.  Therefore, wrapping our original Switch inside of an IF() statement with a HASONEVALUE() condition will allow us to control what happens when the user doesn't select a single value.  In this case, we want the charts to go blank.

Dynamic Measure (HasOneValue) (No Selection)

Dynamic Measure (HasOneValue) (Average Sales)

We hope this enlightened you to the possibilities for Dynamic Measure Switching in DAX.  The possibilities of this technique are nearly endless.  Any type of information that can be conveyed via measures, can be altered with this technique.  Thanks for reading.  We hope you found this informative.

Brad Llewellyn
BI Engineer
Valorem Consulting
@BreakingBI
www.linkedin.com/in/bradllewellyn
llewellyn.wb@gmail.com