Show more than one leader bords

Hi,

I have two leader boards in ios gamecenter. how can i show all leader boards in one button action.

my code is:

           for k,v in pairs(leaderBoards) do

                gameNetwork.show( “leaderboards”, { leaderboard={ category=leaderBoards[k], timeScope=“Week” } } ); 

            end

but it shows only last leader board. please help me…