If it is not practical to run separate queries against a data source in response to a drill across request, you can configure the source and the target so they are in the same document and therefore, depend on the same query. Typically the target is a table with the details and local filters that only apply to that table. Therefore, the pivot acts as a summary and the table acts as the detail without having to return to the data source and retrieve further data.
To configure the Drill Across component for this operation, the Target Query column must be empty, so no process takes place and only local filters are applied for the target structure. The dashboard developer must set up the filters in the source and target structures. Typically in such a configuration the filters that apply to the target structure are not present in the source structure, so that the source pivot does not change as filters are applied to focus the target on the selected details.