Glue previous fiscal period input filter

DATA:
  lv_period TYPE /bi0/oifiscper,
  lv_date   TYPE budat,
  lv_gjahr  TYPE gjahr,
  lv_poper  TYPE poper,

  ls_selopt LIKE LINE OF ct_selopt.

lv_date = sy-datum.

"get previous month date
CALL FUNCTION '/SAPHT/DRM_CALC_DATE'
  EXPORTING
    date      = lv_date
    days      = 0
    months    = 1
    sign      = '-'
    years     = 0
  IMPORTING
    calc_date = lv_date.

"get fiscal period for previous month
CALL FUNCTION 'FI_PERIOD_DETERMINE'
  EXPORTING
    i_budat = lv_date
    i_periv = 'K4'
  IMPORTING
    e_gjahr = lv_gjahr
    e_poper = lv_poper.

CONCATENATE lv_gjahr lv_poper INTO lv_period.

ls_selopt-fieldname   = 'FISCPER'.
ls_selopt-sign        = 'I'.
ls_selopt-option      = 'EQ'.
ls_selopt-low         = lv_period.

APPEND ls_selopt TO ct_selopt.