Sorry but made a mistake in the second formula.
if datepart("q",currentdate)=1 then
datepart("q",{INIDP.INVDAT})=4
and datepart("yyyy",{INIDP.INVDAT})=datepart("yyyy",dateadd("yyyy",1,currentdate)-1)
else
datepart("q",{INIDP.INVDAT})=datepart("q",dateadd("q",-2,currentdate)-1)
and...