How To Filter Enabled A Leaderboard?

Hey, I'm new to scripting and would like to know how to make a leaderboard or leaderstats thats filter enabled so everyone will be able to see when a value change.

I've tried the code below from the wiki, but I want know how to make it so when you click on a text button your "Cash" will increase and other people will see it.

Also is there any easier way to filter enabled a leaderboard other than the one shown below? Thank you for your time. xd

ps. what are those brackets "[]" for and "_, player" mean.

-- Table for holding each player's 'leaderstat' values
local playerLeaderStats = {}

-- Function that executes when a player is added to the game
game.Players.PlayerAdded:connect(
    function(player)
        playerLeaderStats[player] = {}  -- Add a sub-table for the player to the 'playerLeaderStats' table
        playerLeaderStats[player]["Money"] = 0  -- Add a 'Money' key with value of 0

        local leaderstats = Instance.new("Model")
        leaderstats.Name = "leaderstats"
        leaderstats.Parent = player  -- Parent the 'leaderstats' object to the player

        local money = Instance.new("IntValue")  -- Create a new 'IntValue'
        money.Name = "Money"  -- The name of the in-game leader stat
        money.Value = playerLeaderStats[player]["Money"]
        money.Parent = leaderstats  -- Set the money object as a child of the 'leaderstats' object
    end
)

while wait(5) do 
    for _, player in ipairs(game.Players:GetPlayers()) do
        if player:FindFirstChild("leaderstats") then
            -- Don't use the 'IntValue' value because an exploiter can modify it!
            playerLeaderStats[player]["Money"] = playerLeaderStats[player]["Money"] + 1
            player.leaderstats.Money.Value = playerLeaderStats[player]["Money"]
        end
    end
end