You want to display further fields in the line item report FAGLL03

SAP note:

984305 - "Line item: Definition of special fields(T012S)"

 Describes the standard procedure to allow the definition of special fields. Please read these notes for general information and for common topics such as:

• Basic Information

• Troubleshooting and know problems

• Helpful notes

• Definition of special fields 

If you have issues regarding addition of Special Fields , see the following sections. 

First define special fields following customizing paths described in note 984305.

Then include the filed in the ALV layout:

After run the report and check the report output you can go to the  menu "Settings"->"Layout"->"Current..."

The list containing the fields which are included at your layout will appear.

Press "CTRL+SHIFT+F6" in order to display the technical information and check if the first character is "U_".

• Run reports BALVBUFDEL as described in notes 215798.

• Check in SE16 if the field is filled in the table (ex. BKPF-BKTXT). If the field is empty, the issue is in the transaction which posted the document, there is no display issue.
   

The basic structure for displaying the items is FAGLPOSE. From the relevant entries in the table T021S, the system generates the FAGLPOSYEXT structure. The special fields have the prefix "U_". Both structures are included in the structure FAGLPOSX, which is used for the display.

If the field is not in the FAGLPOSX structure, please delete the special fields from T021S and insert it again.

In case when you save or subsequently change the special fields, you receive an error message, for example "Termination with error 3" or F4 308 ("System error: Error in routine GENERATE FAGLPOSYEXT").

In this case, analyze the activation log of the relevant structure. Call transaction SE11 and enter the relevant structure in the "Data type" field:

FAGLPOSYEXT Display the structure.
Then, choose "Utilities -> Activation Log" in the menu.
This log contains exact explanations of which errors occurred.

In certain constellations, the routine AFTER-IMPORT for the table T021S for generating the special fields may not be started correctly.
In this case, start the generation manually. To do this, proceed as follows:

Call transaction SE37, enter the function module ITEM_STRUC_EXTENSION and execute it with the following parameters:

BASIC_STRUCNAME                 FAGLPOSY
EXT_STRUCNAME                  FAGLPOSYEXT
EXT_FIELDS_TABNAME              T021S
I_LSTCL                         D
X_TRANSPORT                     ' '

After you have executed the function module, the structure should be regenerated correctly.

     a) You need to use a field that is not available as special field in T021S

     These special fields can only be taken from the following tables: 

     BKPF, BSEC, BSED, BSEG, PAYR, BSEGC, BSBV.

     If you need to display a field from a different table, then you should use BADI 'FAGL_ITEMS_CH_DATA'

     You can use the following SAP Note as a reference to check how the BTE can be implemented:

         1174945 - FAGLL03: Display of absolute amounts

     b) The use of special fields may cause performance issues in some scenarios.

      Please refer to the following information in order to avoid this kind of issues. 

      1135916 - "Line items: Help for analysis for long runtime"
      1652034-  "Line items display performance enhancement"