Filter-Dependent Business Add-Ins 
Business Add-Ins may be implemented on the basis of a filter value. If an enhancement for country-specific versions is provided for in the standard version, it is likely that different partners will want to implement this enhancement. The individual countries can create and activate their own implementation.
Enter a filter type when defining your enhancement (a country or industry sector, for example). All methods created in the enhancement's interface have filter value FLT_VAL as their importing parameter. The application program provides the filter value for the enhancement method. The method then selects the active implementation for that value.
A description of how a filter-dependent Business Add-In works in the context of the string conversion example follows. Different implementations are called using different filter values.
Defining a Filter-Dependent BAdI
Calling the BAdI from the Application Program
Implementing a Filter-Dependent BAdI
Special Aspects of Country-Specific BAdIs
Calling Implementations Through Filter Mechanisms