Hello Sapper,
Just try this, In VBAK table give your Sales Document in VBELN field and get KNUMV from there. Now pass this value of KNUMV in KONV table in order to fetch the condition value from KWERT and condition type from KSCHL. Also, you can trying developing an Z-report by using this FM CONDITION_RECORD_READ with the help of your developer. Hope this helps. Thanks and ve a good day.