How would I illiterate over this to see which area the player is in with PartBoundsInBox?

In my previous post, I was trying to fix the issue with the sound not playing when entering the zone which I fixed on my own. Now with more islands in the game, I need this to go through all of the CFrames and their sizes to see where the player is currently is to play the islands respective music.

local player = game.Players.LocalPlayer
local character = player.Character or player.CharacterAdded:Wait()
local music = game:GetService("SoundService")
local TS = game:GetService("TweenService")
local rems = game:GetService("ReplicatedStorage").Rems

local CFs = {
	cf_highland = CFrame.new(50,155,35),
	cf_lowtide = CFrame.new(-693,45,487)
}
local Sizes = {
	cs_highland = Vector3.new(134,113,134),
	cs_lowtide = Vector3.new(222,290,261)
}

local returnWhiteList = {character:WaitForChild("HumanoidRootPart")}

-- when a new character loads, set it to be the white list 
-- this allows the music to be heard after the first character dies
player.CharacterAdded:Connect(function(char)
	returnWhiteList = {char:WaitForChild("HumanoidRootPart")}
end)

local returningTable

local TI1 = TweenInfo.new(0.75, Enum.EasingStyle.Linear, Enum.EasingDirection.In)
local TI2 = TweenInfo.new(0.75, Enum.EasingStyle.Linear, Enum.EasingDirection.Out)

rems.LoadPlr.OnClientEvent:Connect(function()
	game:GetService("RunService").Heartbeat:Connect(function()
		local filteringType = Enum.RaycastFilterType.Whitelist
		local tempsize = Vector3.new(134,113,134)
		local tempcf = CFrame.new(50,155,35)
		
		local overlapParams = OverlapParams.new()
		overlapParams.FilterType = filteringType
		overlapParams.FilterDescendantsInstances = returnWhiteList
		
		returningTable = workspace:GetPartBoundsInBox(tempcf, tempsize, overlapParams)
		
		if returningTable[1] ~= returnWhiteList[1] then
			TS:Create(music.Highland_Isle, TI2, {Volume = 0}):Play()
			TS:Create(music.SailingTheme, TI1, {Volume = 0.5}):Play()
		else
			TS:Create(music.Highland_Isle, TI1, {Volume = 0.5}):Play()
			TS:Create(music.SailingTheme, TI2, {Volume = 0}):Play()
		end
	end)
end)

The arrays I want to loop through are,

local CFs = {

cf_highland = CFrame.new(50,155,35),

cf_lowtide = CFrame.new(-693,45,487)

}

local Sizes = {

cs_highland = Vector3.new(134,113,134),

cs_lowtide = Vector3.new(222,290,261)

}

I’m just super confused on how I would implement this using PartBoundsInBox.