What does the identifier '$1' indicate in Qlik Sense?

The identifier '$1' in Qlik Sense indicates the previous selection within the context of set analysis. This identifier allows users to reference the state of a selection prior to the most recent change. In the context of building expressions or visualizations, it enables the analysis of what was selected before the current selection was made, providing a way to compare data or derive insights based on historical interactions.

This functionality is particularly useful for creating comparative analyses, where you may want to see how values have changed based on user input or selections. By utilizing '$1', users can effectively track changes in data selections over time and leverage this information for deeper insights within their Qlik Sense applications.

Other identifiers such as '$' represent the current selections, while different notations are used to indicate future selections or manipulate data differently. Understanding these nuances is essential for advanced data manipulation and analysis in Qlik.