The following will return data when the line : FY_Period = {"<=$(=vFYPeriod)"}>},
is NOT used.
The variable FYPeriod is numeric and is defined as =Max( distinct FY_Period) and I tried without distinct
The aim is to return records for a particular year, up to and including the period , so currently period 11, which is March 2014 in the example since we are taking 1 from the FY.
I am not an expert in set analysis, but I did notice that your expression FY_Period = {"<=$(=vFYPeriod)"}>} has 2 closing curly brackets } but only one opening {. I have a feeling that cannot be correct.