We are using several reports which are connected via actions "Go to report". Since each of the reports has multivalued parameters which are filled from data sets and depend on each other, we encounter the following problem. If a set of values of a multivalued parameters is passed from a report A to a report B where the same multivalued parameter has less selection options, then the selection of this parameter in report B will be empty (no selection at all will be made). The wanted behavior is to construct the intersect of available and passed selection options (e.g. passed are X,Y,Z and available are W,Y,Z --> Y,Z should be selected). To achieve this, we circumvented the problem by using custom code to determine the needed intersect and passed that instead of the full list. This "solution" consists of aggregate functions, scope checks and so on. It is rather complicated and definitely not the preferred way to go. Does anyone know if there is a way to reconfigure the SSRS so that it construct the intersection of both sets of values on its own and thus not showing a blank selection of the multivalued parameter? Another probable solution could consists of an assembly implementing a custom aggregate function. This custom aggregate function or its use should not depend of the available aggregate function like First, Last, or RunningValue. What I mean is that this custom aggregate function should be able to work on grouped data on its own. Is that possible to realize? Thanks -- Dominic