Sort matching values first

I would like to sort/boost some products to the top on my searchresult, I have a parameter on the products with budget period, yyyyx (where yyyy is budget year and x is 1 or 2 (first or second half of the year)).

So we can set a dropdown to: 0, 1, 2 and based on that value I want to sort/boost the result from find to that selected value.

I need to compare the selected valute to the last character of the property in find.