You can do this through parameters by bucketing your measure in the specific data range e.g.. Sum(if ([date] < [parameter 1] and [date] > [parameter 2]) then [Sales] end )
Unfortunately though you will need TWO parameters for each scenario to define the range as a parameter can only be a distinct point and not a range.
Thanks John. This is very helpful. I wanted to select specific weeks for comparisons. Have used OR condition with parameter to achieve this. Your suggestion helped save me long hours of struggle.