I would ask myself "Is it mango first, then beer, or is it Belgian Beer first, then mango" and enter it accordingly. I.E. - Mango first would be in "fruit beer" and Belgian first would be in "Belgian Specialty".
Or you could enter it in both
Brewing since 1989 - BJCP National Rank
Fermenting: McChouffe clone, Samiclaus clone
Conditioning: Belgian Tripel, Barrel Aged Baltic Porter - in sherry barrel, Belgain Easter Ale
On tap: CAP, Dortmunder Export, IIPA, Dubbel Chocolate Stout, Wee Heavy, Whiskey barrel aged Wee Heavy, Baltic Porter