SAP Function Module search on BS_PE
Search FMs
BS_PERIOD_SH_DEST_FRQ_TYPE - Search Help for Destination Frequency Type
BS_PERIOD_SH_FRQ_UNIT - Search help exit for BSPERIOD_FRQ_UNIT
BS_PERIOD_SH_SRC_FRQ_TYPE - Search Help for Source Frequency Type
Return Table index