(Glue-2002) Q: Why are multiple BAdi-s applied when using dynamic (ABAP) selection?

The execution of particular BAdi implementation is triggered by calling BAdi with filter value.
E.g. when a selection with "$ABAP_FILTER" value is defined in Glue variant, all BAdi-s with filter definition equal to "$ABAP_FILTER" will be executed.
Moreover the SAP logic executes also BAdi-s with no filter definition, assuming it is the logic that should be executed regardless the filter.
Therefore, when implementing BAdi enhancements for Glue variant filtering, always specify the filter value to ensure that no unwanted logic will be executed.

In the next image the correctly defined BAdi implementation is shown: