There are different ways to search a business add-ins :

• Search for the string ‘CL_EXITHANDLER’ in the relevant application program. If you call a business add-in from the program, you must also call the ‘GET_INSTANCE’ in this class.
• Double-click the reference variable and note the name of the interface used.
• Using class Builder (SE24), display the where used list of the interface to retrieve the business add-in definition class  (CL_EX_BADI).
• The BADI definition contains documentation and a guide and implementation guide of the business add-in.
• You can also use search tools.
• However, you can also use application hierarchy to limit the search to certain components.
• Start SE80, select  Repository Information System -> Enhancements -> Business Add-Ins to open the relevent search program.
• You can also use the relevant entries in the implementation guide.