Specifies cross filtering direction to be used in the evaluation of a DAX expression. The relationship is defined by naming, as arguments, the two columns that serve as endpoints.
The third argument to the CROSSFILTER function should be 0 for None or 1 for OneWay, or 2 for Both. It is also possible to use words None, OneWay, Both.
The function returns no value. The function only sets the cross-filtering direction for the indicated relationship, for the duration of the query.
In the case of a 1:1 relationship, there is no difference between the one and both direction.
CROSSFILTER can only be used in functions that take a filter predicate as an argument, for example: CALCULATE, CALCULATETABLE, CLOSINGBALANCEMONTH, CLOSINGBALANCEQUARTER, CLOSINGBALANCEYEAR, OPENINGBALANCEMONTH, OPENINGBALANCEQUARTER, OPENINGBALANCEYEAR, TOTALMTD, TOTALQTD and TOTALYTD functions.
CROSSFILTER uses existing relationships in the model, identifying relationships by their ending point columns.
In CROSSFILTER, the cross-filtering setting of a relationship is not important; that is, whether the relationship is set to filter one, or both directions in the model does not affect the usage of the function. CROSSFILTER will override any existing cross-filtering setting.
An error is returned if any of the columns named as an argument is not part of a relationship or the arguments belong to different relationships.
If CALCULATE expressions are nested, and more than one CALCULATE expression contains a CROSSFILTER function, then the innermost CROSSFILTER is the one that prevails in case of a conflict or ambiguity.
Learn more about CROSSFILTER in the following articles:
Many-to-many relationships in Power BI and Excel 2016
The new DAX available in Excel 2016 and the data model in Power BI and Analysis Services 2016 offer tools to manage many-to-many relationships in a more efficient way than previous version, as described in this article. » Read more
Bidirectional relationships and ambiguity in DAX
Activating bidirectional cross-filter in a Tabular data model might create ambiguous paths in the chain of relationships, resulting in very dangerous models as numbers become unpredictable. This article provides a deep explanation of the kind of ambiguity that might appear… » Read more
Other related functions are:
Contributors: Alberto Ferrari, Marco Russo
MSDN documentation: https://docs.microsoft.com/en-us/dax/crossfilter-function