Year1 = {{'Y2007','Y2008','Y2009','Y2010','Y2011'}; {'Y2004','Y2005','Y2006','Y2007','Y2008','Y2009'};{'Y2007','Y2008','Y2009','Y2010','Y2011'}};
Year2 = {{'Y2005','Y2006','Y2007','Y2008','Y2009','Y2010','Y2011'}; {'Y2005','Y2006','Y2007','Y2008','Y2009','Y2010','Y2011'}; {'Y2005','Y2006','Y2007','Y2008','Y2009','Y2010','Y2011'}};
Year = cellfun(@intersect,Year1,Year2,'un',0)
OR in this is case
Year1 = {{'Y2007','Y2008','Y2009','Y2010','Y2011'}; {'Y2004','Y2005','Y2006','Y2007','Y2008','Y2009'};{'Y2007','Y2008','Y2009','Y2010','Y2011'}}
Year2 = {'Y2005','Y2006','Y2007','Y2008','Y2009','Y2010','Y2011'};
Year = cellfun(@(x)intersect(x,Year2),Year1,'un',0)