Counting true values within a table?

One way that you could achieve this is by iterating through the Players service, finding out who has their BoolValue (Playing) set to true, add them to a table and then have a function return the table for you to use.

E.g.

function GetPlayers()
    local Playing = {}
    for _, Player in pairs(game.Players:GetPlayers()) do
        if Player:FindFirstChild("Playing") and Player.Playing.Value then
            Playing[#Playing +1] = Player
        end
    end
    return Playing
end

local Playing = GetPlayers()
if #Playing >= 2 then 
    print("More than two players have set their Playing BoolValue to true!")
    for _, Player in pairs(Playing) do
        if Player.Character then
            Player.Character:MoveTo(Vector3.new(0, 200, 0)) 
        end
    end
end

You could also use the table being returned by the 'GetPlayers' function to teleport the users, etcetera, without the need of iterating through the entire Players service again. An example of this can be found between lines 14 and 18.

If you need anything explained further, just leave a comment to this reply.