Power BI Field Parameters let developers create slicers that enable users to switch out which fields are being displayed on a visual at any given point. It’s a much more elegant solution than using buttons to switch between hidden tabs, and gives report viewers a way to interact with more dynamic visuals than they would otherwise be able to.
We’ll explain how field parameters can be used to create dynamic visuals where users can change out field values on Power BI visuals for an extremely dynamic experience.
Let’s dive in!
Table of Contents
What are Power BI Field Parameters
Power BI Field Parameters are a way to use a slicer, an on-page filter, to switch between different fields that have been assigned to a visual. They enable report viewers to select which columns, or measures they see in charts and graphs giving them additional options that would not be available with traditional filtering methods.
The example below shows a slicer on the left side, that allows users to switch between Expense Types for Rent, Utilities or Wages. When a report viewer selects a type, Power BI replaces the field assigned to the Line y-axis with the name of the selected column.
Field parameters can be made up of fields, columns, custom measures, or any combination of them. As long as the field or calculation is available in the data tab, you can add it to a field parameter.
Developers can also assign multiple field parameters to a single visual making it highly dynamic to the point that report viewers can adjust and see almost any combination of column, measure or field.
Why are Field Parameters Important?
Field Parameters were released in November 2022 and have been one of the most exciting feature additions to Power BI since it was first released in 2015. To fully appreciate why, it’s useful to know what the process was for creating highly dynamic visuals previously.
Before field parameters were introduced, Power BI developers had to create multiple versions of the same visual to allow users to switch between views. It often required the creation of numerous bookmarks to support all of the different possible views and assign them manually to slicers where users could switch between them. It was an effective workaround, but highly time consuming.
Now let’s look at how to set them up!
How to Create a Power BI Field Parameter
To create a field parameter in Power BI, navigate to the Modeling Tab in the report view, click on New Parameter, and select Fields. This launches the Parameter Editor where fields or measures are assigned to the new parameter. Select the fields or measures you want to include in the parameter and click Create. A new Field Parameter Measure will be available on the data panel to assign to visuals.
The following breaks down the process for creating field parameters into more detail.
Step 1.) Launch the Field Parameter Editor
Navigate to the Modeling tab of the Power BI Ribbon on the Report View. The New Parameter button is in the middle.
Then Select Fields for a new Field Parameter.
This launches the Power BI Field Parameter Editor. While you’re working in the editor, make sure to update as many fields as possible, this editor essentially creates a big DAX formula. Future editing is done by either editing the formula, or you have to create a new Field Parameter at this time.
Step 2.) Assign columns or measures to the Field Parameter
The right side of the screen shows you all of the fields and measures that you currently have available. Check the boxes next to them and they will move to the left side of the screen. These are the columns that become available for people to choose from when using a slicer.
Re-name the field parameter and select whether you want Power BI to automatically generate a slicer. You can create one manually later and assign the field parameter if you don’t want one automatically created.
When setting up items in the Field Parameters wizard, make sure to give your new Field Parameter a name. This is the name that will show up in the Data Panel.
Also, remember to update any field names. You can update the name of each field by double clicking on the name and typing over it. If you don’t make updates now, you can make them later by editing the DAX formula, but there’s no easy way to click edit on an existing field parameter to be brought back to this screen.
Step 3.) Assign the New Field Parameter to a Visual
Once you create a Field Parameter in Power BI, it appears in the Data Panel on the right side. If not immediately visible, you might need to expand the panel. This parameter functions like a placeholder and can be assigned to visuals just like any standard field or measure. However, it’s unique in that the field selected through a slicer is used to the automatically update the visual.
Note: Be careful when setting up slicer settings. Field Parameter slicers can be set to allow single select or multi-select. Depending on your end users they may multi-select many different fields and cause the visual to show unintended results and be confusing for the report viewer.
Creating Dynamic Power BI Visuals with Multiple Field Parameters
One cool trick you can do with Field Parameters is use multiple field parameters in a single visualization. The example below uses two sets of different columns and measures, but you could also provide a large list of options that are the same. Try creating a new Parameter with a different name than the first one and assign the same fields.
You can assign fields even faster, by copying and pasting the DAX formula for a field measure into a new one after it’s created.
This technique is incredibly useful when working with reports that have to serve a lot of different managers or business units. It’s difficult to make a one size fits all report when people are interested in different metrics, this method allows report viewers to create dynamic reports and select their own X and Y axis or whatever the setting may be.
How to Edit a Power BI Field Parameter
After creating the initial field parameter, you can edit it through the DAX formula editor in Power BI. The screenshot below highlights an example Field Parameter formula. Each row is made up of 3 sections. The first is the name that shows up in the slicer. The second is the table and field or measure value that it represents. The number on the far right of each row sets the sort order that the option shows up in the slicer.
Each row is separated by a comma, and you can also copy and paste field parameter formulas between field parameter measures.
Limitations of Field Parameters
There are several limitations when working with field parameters, the biggest one is that you can’t use field parameters with Q&A or AI visuals. If you try to assign a field parameter to one of these visualization types it might not give you an error but it could give you bad results or results that are so vague that they’re mostly meaningless.
A field parameter also has to be selected, there’ is no clear selection option. If you try to not select a field Parmeter value the visualization will default to select all which can be confusing for report viewers. We recommend that developers consider turning on single select mode for parameter slicers to avoid overcrowded visuals.
Field parameters were a welcome addition to Power BI. They not only save developers hours of work creating custom views and buttons as workarounds, but they enable report viewers to get to the data they want, in the way they want to see it dynamically.
We still recommend developers put some safety guards around field parameters to create a curated experience. Even though it’s possible to add dozens or more columns to let people mix and match across a plethora of visuals it can lead to slow performance, and also provide misleading information if the report viewer isn’t aware of how to interpret it. As a Power BI developer, they may go to you to explain results they get from awkward combinations of fields and measures.