Visualizations in a Power BI report use data from the Power BI model in two ways. First, values from columns are used to populate visual elements like the axis in a column chart, row labels in a table visual, or selection items in a slicer. We use the term label to generically refer to these elements. Second, aggregated data from the model, typically in the form of DAX measures, provides the results that a visual represents. While it is not visually clear, the buckets or wells that are used to bind a visual to data fields distinguish between these two types of data usage. For instance, the buckets Axis and Legend demand label data and the Values bucket needs aggregated data:

Figure 2.2.1: Field buckets for a Power BI visual

While Power BI provides many ways to create compelling reports out of the box, sometimes you want to go beyond these. This chapter presents approaches to dynamically change both ways of data binding through DAX....