https://sapcodes.com/2019/12/11/custom-button-select-all-deselect-all-and-filter-option-in-oops-alv-using-cl_gui_alv_grid-class/

Selection Screen: DATA: bdcdata LIKE bdcdata OCCURS 0 WITH HEADER LINE. CLEAR bdcdata. bdcdata-program  = 'SAPLFSH_PP_PCW'. bdcdata-dynpro   = '0025'. bdcdata-dynbegin = 'X'. APPEND bdcdata. lv_partner = p_mloc. SHIFT lv_partner LEFT DELETING LEADING '0'. lv_werks = lv_partner. CLEAR bdcdata. bdcdata-fnam = 'S_PWWRK-LOW'. bdcdata-fval = lv_werks. APPEND bdcdata.…

Normally used for modifying the SAP standard programs. With Modification Assistant on, you can only…