Categorization of the field & using as a filter

Hello All,

I have a field "BIN" in the database. BIN is 17 digit Alpha Numeric Ex: "1FADP5CU3DL511124" . Look at the letters 5, 6 & 7 highlighted in red color.

If letters in the position 5,6 & 7 is P5C or POP or POS then i need to categorize BIN to a category called 'P'.

If letters in the position 5,6 & 7 is P3R then i need to categorize BIN to a category called 'B'.

After categorizing the BIN field, i need to use the field as filter and the filter should have 'P', 'B' & 'All' (Incase client would like to see all category).

How can we do this? 

Best Regards

Sandeep