Project: QGIS
Version: 2.14.0
This introduces two new options to filter legend elements.
The first, filter by expression, allows users to set an expression for filtering which features should be shown in the legend. Only symbols with a matching feature will be shown in the legend.
The second filter option allows a composer legend to be filtered to only include items which are contained within the current atlas polygon.
This feature was developed by Hugo Mercier (Oslandia)