How to populate data in MPP through F4 search help(the field should get filtered as per key)

Question

Dear Experts.
I am new to ABAP and hence trying jmy hands on various ways of peforming a task.
I have a requirement. I want to maintain a database tables through MPP :  ZLT_Auftrag (Refer Screen Shot 1: Doubt MPP1) and ZLT_Kunde (Refer Screen Shot2: Doubt MPP2)
The fields of ZLT_Kunde are: K1, K2, K3
The fields of ZLT_Auftrag are: A1, A2, A3, A4, P1 P2 and P3 are related as per the key field "A3"   (Here A3 = K2)
I want the User to be able to Maintain this table through the Screen that I had created using MPP. (Plz refer the attached Screen Shot3:Doubt MPP3  of the SCREEN in MPP)
When I populate the Kunde name(K1) in the SCREEN (Can be done by F4 Search help), then on hitting the pushbutton "Get Kunde" the  kunde Code (K2) appears . Now from here it can be deleted or even a new Kunde name and code can be saved dirctly to the database table : ZLT_Kunde. (Refer Screen Shoot4: Doubt MPP4)
For Example for Kunde (K1)= BASF, Kunde Code (K2) = BSF, the Auftrag should be all those values from ZLT_Auftrag (where A3 = BSF)
When I try to populate the Auftrag value on the SCREEN then on hitting F4 (already created for table ZLT_Auftrag in se11) then I get all the values of Auftrag (A1) from the table ZLT_Auftrag. (Ply refer Screen Shot 5: Doubt MPP5)
MY REQUIREMENT: Here I want that either through F4 help or through drop down ONLY those values of Auftrag-A1 should appear on the SCREEN which satisfies the condition: A3 = K2
I am unbale to get how to do that.
I need your valuable suggstions.
Regards
Chandan

Answer 1

And the  code of the MPP is:
*& Module Pool       SAPMZDEMO_MPOOL_03
PROGRAM  SAPMZDEMO_MPOOL_03.
TABLES:  ZLT_MITA, ZLT_Kunde, ZLT_Auftrag, Zlt_Stdsatz.
DATA: flg_lock  TYPE c,
*      indx  TYPE i,
*      indxk TYPE i,
*      indxa TYPE i,
*      TCNT TYPE sy-tabix,
      lv_msgv1  TYPE  sy-msgv1.
*DATA: it_mita    TYPE TABLE OF ZLT_mita,
*      it_kunde   TYPE TABLE OF ZLT_KUNDE,
*      it_auftrag TYPE TABLE OF ZLT_AUFTRAG.
*&      Module  STATUS_9000  OUTPUT
*       text
module STATUS_9000 output.
  SET PF-STATUS 'ZSTATUS01'.
*  SET TITLEBAR 'xxx'.
  If flg_lock is Not initial.
    LOOP at Screen.
  If screen-group1 = 'G1'.
  Screen-input = 0.
  MODIFY SCREEN.
       Endif.
    ENDLOOP.
      MESSAGE s000(8i) WITH 'Mitarbeiter already locked by user' lv_msgv1.
  ENDIF.
endmodule.                 " STATUS_9000  OUTPUT
*&      Module  USER_COMMAND_9000  INPUT
*       text
module USER_COMMAND_9000 input.
*To Populate Data into Mitarbeiter through Pushbuttons
  CASE sy-ucomm.
    When 'OK_GET'.
      Clear : flg_lock.
        IF ZLT_MITA-M1 is NOT INITIAL.
            SELECT SINGLE *
            FROM  ZLT_MITA
            Where M1 = ZLT_MITA-M1.
*To create a Lock Object so that when two or more employees are accessing the same data
* at the same time then for the new user the data gets locked and only can been seen in
*display mode
        IF sy-subrc = 0.
        CALL FUNCTION 'ENQUEUE_EZLT_MITALOCK'
         EXPORTING
           MODE_ZLT_MITA        = 'E'
           MANDT                = SY-MANDT
           M1                   = ZLT_MITA-M1
*           X_M1                 = ' '
*           _SCOPE               = '2'
*           _WAIT                = ' '
*           _COLLECT             = ' '
         EXCEPTIONS
           FOREIGN_LOCK         = 1
           SYSTEM_FAILURE       = 2
           OTHERS               = 3
        IF sy-subrc <> 0.
          flg_lock = 'X'.
          lv_msgv1 = sy-msgv1.
        ENDIF.
        ENDIF.
        ELSE.
            MESSAGE S000(8i) With 'Enter Mitarbeiter Name'.
        ENDIF.
    When 'OK_SAVE'.
       Modify ZLT_MITA.
       IF sy-subrc = 0.
         MESSAGE s000(8i) With 'Data Saved'.
       ENDIF.
    When 'OK_DELETE'.
        IF ZLT_MITA-M1 is NOT INITIAL.
            DELETE
            FROM  ZLT_MITA
            Where M1 = ZLT_MITA-M1.
          IF sy-subrc = 0.
            MESSAGE S000(8i) With 'Data deleted'.
          ENDIF.
        ENDIF.
*     When 'OK_FIRST'.
*           indx = 1.
*     When 'OK_NEXT'.
*           indx = indx + 1.
*     When 'OK_PREV'.
*           indx = indx - 1.
*     When 'OK_LAST'.
*           Describe Table it_mita lines indx.
*To Populate Data into Kunde through Pushbuttons
    When 'OK_GETK'.
        IF ZLT_Kunde-K1 is NOT INITIAL.
            SELECT SINGLE *
            FROM  ZLT_Kunde
            Where K1 = ZLT_KUNDE-K1.
        ELSE.
            MESSAGE S000(8i) With 'Enter Kunde Name'.
        ENDIF.
    When 'OK_SAVEK'.
       Modify ZLT_Kunde.
       IF sy-subrc = 0.
         MESSAGE s000(8i) With 'Data Saved'.
       ENDIF.
    When 'OK_DELETEK'.
        IF ZLT_KUNDE-K1 is NOT INITIAL.
            DELETE
            FROM  ZLT_KUNDE
            Where K1 = ZLT_KUNDE-K1.
          IF sy-subrc = 0.
            MESSAGE S000(8i) With 'Data deleted'.
          ENDIF.
        ENDIF.
*To Populate Data into Auftrag Through Pushbuttons
    When 'OK_GETA'.
        IF ZLT_KUnde-K2 is NOT INITIAL.
            SELECT SINGLE *
            FROM  ZLT_Auftrag
            Where A3 = ZLT_Kunde-K2.
        ELSE.
            MESSAGE S000(8i) With 'Enter Kunde Name'.
        ENDIF.
    When 'OK_SAVEA'.
       Modify ZLT_Auftrag.
       IF sy-subrc = 0.
         MESSAGE s000(8i) With 'Data Saved'.
       ENDIF.
    When 'OK_DELETEA'.
        IF ZLT_Auftrag-A1 is NOT INITIAL.
            DELETE
            FROM  ZLT_Auftrag
            Where A1 = ZLT_Auftrag-A1.
          IF sy-subrc = 0.
            MESSAGE S000(8i) With 'Data deleted'.
          ENDIF.
        ENDIF.
*To Populate Data into Position Thorugh Pushbuttons
    When 'OK_GETP'.
        IF ZLT_Auftrag-A2 is NOT INITIAL.
            SELECT SINGLE *
            FROM  ZLT_Auftrag
            Where A3 = ZLT_Kunde-K2.
        ELSE.
            MESSAGE S000(8i) With 'Enter Kunde Name'.
        ENDIF.
    When 'OK_SAVEP'.
       Modify ZLT_Auftrag.
       IF sy-subrc = 0.
         MESSAGE s000(8i) With 'Data Saved'.
       ENDIF.
    When 'OK_DELETEP'.
        IF ZLT_Auftrag-A1 is NOT INITIAL.
            DELETE
            FROM  ZLT_Auftrag
            Where A1 = ZLT_Auftrag-A1.
          IF sy-subrc = 0.
            MESSAGE S000(8i) With 'Data deleted'.
          ENDIF.
        ENDIF.
    When 'OK_EXIT'.
       Leave Program.
    When 'OK_CLEAR'.
      Clear : ZLT_MITA, ZLT_KUNDE, ZLT_AUFTRAG.
*              it_mita, it_kunde, it_auftrag,
      CALL FUNCTION 'DEQUEUE_EZLT_MITALOCK'
       EXPORTING
         MODE_ZLT_MITA       = 'E'
         MANDT               = SY-MANDT
         M1                  =  ZLT_MITA-M1
*         X_M1                = ' '
*         _SCOPE              = '3'
*         _SYNCHRON           = ' '
*         _COLLECT            = ' '
ENDCASE.
endmodule.                 " USER_COMMAND_9000  INPUT
*&      Module  user_cmd_9000  INPUT
*       text
module user_cmd_9000 input.
  If sy-ucomm = 'OK_CANCEL'.
  LEAVE PROGRAM.
  ENDIF.
  IF sy-ucomm = 'OK_EXIT'.
      LEAVE PROGRAM.
  ENDIF.
endmodule.                 " user_cmd_9000  INPUT