Precedence rules provide a way to delay the display of dimensions until they offer a useful refinement of the navigation state.
Precedence rules are defined in terms of a trigger dimension value and a target dimension, where a user's selection of the trigger dimension value reveals the previously unavailable target dimension to the user.
For example, one might not want both the Country and State dimensions to appear simultaneously in a geographical data set. A precedence rule could be defined so that the State dimension would appear only after a dimension value from the Country dimension is selected. This simplifies the user's navigation choices and avoids information overload by hiding the State dimension until it is relevant to the navigation state.
A target dimension associated with more than one precedence rule is exposed when at least one associated trigger dimension value is selected.
For example, assume we have three dimensions: Author, Region, and Language. We have two precedence rules:
Region > Author Language > Author
In this case, the Author dimension is displayed after a dimension value from either the Region or Author dimension is selected.
