SELECTION-SCREEN BEGIN OF BLOCK VARIBLE WITH FRAME TITLE TEXT-001.
parameters filename like rlgrap-filename DEFAULT 'c:\'.
SELECTION-SCREEN END OF BLOCK VARIBLE.
Data: str1 type string.
AT SELECTION-SCREEN ON VALUE-REQUEST FOR filename .
  CALL METHOD cl_gui_frontend_services=>directory_browse
    EXPORTING
      window_title         = 'Выберите путь, пожалуйста'
      initial_folder       = 'C:\'
    CHANGING
      selected_folder      = str1.
filename = str1.