@Guillermo Cuadrado beat me to it - I must agree.
I very much appreciate that Appto BI distinguishes between "empty" and "zero", as too many tools wrongly assume otherwise; but it would be helpful to have a "show NULL as ..." display option on the fields. There are other cases where BI's handling of NULL is incomplete, such as Drill Tables.
That said, I'm surprised that Hyperion doesn't an input transformation function that could handle the N/A.
I must go check and ensure I've put in the BI feature requests that match my earlier "BI Beta" feedback items about NULL.
#ApptioBI