Option 1: Use a level of detail expression inside of the RANK_DENSE() function

Option 2: Manually calculate the measure values for every ranking level

1. Create a calculated field with a name like "Highest Sales Values" with a calculation similar to the following:

   { FIXED : MAX( { INCLUDE [Segment], [Category] : SUM([Sales] ) } ) }

2. Create a calculated field with a name like "2nd Highest Sales Value" with a calculation similar to the following:

   { FIXED : MAX( { INCLUDE [Segment], [Category]:
   	IF SUM([Sales]) < SUM([Highest Sales Values])
   	THEN SUM([Sales])
   	END
   	})}

3. Repeat step 2 for as many rank levels as desired, replacing [Highest Sales Values] with the lowest value above the current rank.
4. Create a calculated field with a name like "Rank (just LOD)" with a calculation similar to the following:

   IF { FIXED [Segment], [Category] : SUM([Sales])} = [Highest Sales Values]
   	THEN 1
   	ELSEIF { FIXED [Segment], [Category] : SUM([Sales])} = [2nd Highest Sales Value]
   	THEN 2
   	ELSEIF { FIXED [Segment], [Category] : SUM([Sales])} = [3rd Highest Sales Value]
   	THEN 3
   	END