IIf function often used in MultiDimensionalExpression (MDX), It’s quiet simple to implement single block of IIf block.
This an example of Multiple IIf logic block.
Example1:
IIf(Measures.[Store Sales] > 50000, "Good",
IIf(Measures.[Store Sales] > 30000, "Average",
IIf(Measures.[Store Sales] > 10000, "Poor",
"No")))