Making a filter who includes more data series
If you want a filter to include more than one data series, it is important that the path to the variables, including URIs of the resources, is the same.
Lets say you want to filter on counties, and both of the data series includes information about which municipalities it is about. The municipalities again, includes information about which county it belongs to. So long as we keep the path the same, this is a easy task.
Keeping the path the same is the equvalent as using the same properties for saying which data belongs to which municipalities. See more under "Making shared properties" here: Making_ontologies
See the old way of doing this: Tutorial4 OLD