Comparing with previous selected time period in DAX
Time intelligence calculations in DAX are usually created considering consecutive periods in any type of comparisons. This approach might not work well when the requirement is to compare the differences between a selection of non-consecutive periods. In that case, the “previous” element in a visualization might not correspond to the previous element in the data model.
For example, consider the following report where the slicer selects an arbitrary set of months within a year: March, May, August, and October 2008.