ssrs tune ssas date hierarchy as parameter

i am creating a SSRS report, which use adventure works cube as data source, and i want parameter like thisJan 2015, Feb 2015, Mar 2015.... if i use hierarchy from date dimension, it will give me semester, quarter, month, date into parameter list, which is not i want.but if i use member in the date dimension, then it will give me like 12 March 2015, 13 March 2015, ...., all i want is month and year prompt out as parameter.has anyone know how to do this? many thanks