chord_toggle_visibility.lua

function plugindef()
    finaleplugin.RequireSelection = true
    finaleplugin.Author = "Nick Mazuk"
    finaleplugin.Copyright = "CC0 https://creativecommons.org/publicdomain/zero/1.0/"
    finaleplugin.Version = "1.0"
    finaleplugin.Date = "July 2, 2019"
    finaleplugin.CategoryTags = "Chord"
    finaleplugin.AuthorURL = "https://nickmazuk.com"
    return "Toggle Chord Visibility 2", "Toggle Chord Visibility 2", "Toggles the chords' visibility"
end

function chord_toggle_visibility()
    local musicRegion = finenv.Region()
    musicRegion:SetCurrentSelection()
    local chords = finale.FCChords()
    chords:LoadAllForRegion(musicRegion)
    for chord in each(chords) do
        chord.ChordVisible = not chord:GetChordVisible()
        chord:Save()
    end
end

chord_toggle_visibility()