I found this very useful in situations where we have for example a fact sales amount and want to group sales into small, medium and large. I have used range dimensions with range, min, max. I then use a table like below to look up the range by using a between SQL statement

range min max
Small 1 1000
Medium 1001 5000
Large 5001 10000000

Here is a much easier way

Dimensional Modeling with Ranged Dimensions