Ranking Issues with Measures

[Anonymous]

I would like to create a Top 5 and Bottom 5 ranking based off of a Measure that is interactive based off of the filter selections.

A picture is posted below(Dummy Data).. That I will further explain

So in the table I have a Market Column which is in my "Geography" Table and I have a category column which is in my "Retailer Table"... POS USD TY and POS USD LY are both measures (Foreign Currency/USD Conversion Rate) ... IYA is another measure that is taking POS USD TY / POS USD LY *100... I would like to have another column that ranks The Top 5 IYA's and Bottom 5 IYA's...

As I choose my time filter -- Last Week ,Last 4 Weeks, Last 52 Weeks I want the table and ranking systems to change based off selections. Currenlty I'm stuck and don't know what formula to use..  TOPN as a visual filter does not work .. I know I need a Rankx formula.. Please help!!!