MDX: Make Measure Value 0 based on flag

Would much appreciate any help on this.

I have a measure called "Sales" populated with values, however i am trying to turn the "Sales" value to 0, whenever the "Sales Flag" is set to 0.

Important Note: The Sales Flag is based on Date (lowest level of detail).

The difficulty that i am really experiencing and cant get a grip on, is how i am trying the display the MDX outcome.

As explained above, i would want to make the "Sales" value 0 whenever we have a 0 in the "Sales Flag" (which is based on the Date), but when I run the MDX Script I would wan't on the ROWS to NOT display the Date, but instead just the Week (higher Level to Date), as below shows:

I really have spent hours on this and can't seem to understand how we can create this needed custom Sales measure based on the Sales Flag on the date level, but having the MDX outcome display ROWS on Week level.

Laz