Is there a way for my object to locate any node from the scene it appears in?

LoveLearningGD

I have my main Godot game scene called "Game".
To access any node in this scene I use get_node() and $node.
I created a new Godot scene named "Shape". In this scene block I made only a 2D square.
In my Game scene I spawned my 2D square in.
However, when I use get_node() or $, there is no way for my Square to locate any nodes from my Game scene because it originates from a different scene.

My goal is to have my 2D square tell my Game scene to play a sound when I spawn in that 2D Square.
The sound gets louder for each 2D square spawned in.
The sound gets quieter when one gets destroyed on screen.

I have tried using signals as well but to my knowledge even that requires listening to a node.
I also do not want to add the sound to my 2D square itself or use global variables.

Thank you if you decide to help me,

_{LoveLearningGD}

BroTa

LoveLearningGD However, when I use get_node() or $, there is no way for my Square to locate any nodes from my Game scene because it originates from a different scene.

$../SomeChildOfGame # $../ access parent node, $../../ parent of parent etc..

LoveLearningGD I have tried using signals as well but to my knowledge even that requires listening to a node.

What did you mean by that?

LoveLearningGD My goal is to have my 2D square tell my Game scene to play a sound when I spawn in that 2D Square.

Keyword here is, tell
The child node can tell its parent to do stuff via signals
To do that:
In your Shape scene script, make a new signal
signal player_spawned
When you spawn the player, emit this signal
player_spawned.emit() # this is a godot 4 syntax, if you use 3.x, please read the docs
In the Game script, connect this signal to some function you make
$PathToShape.player_spawned.connect(_on_shape_player_spawned) # this is a godot 4 syntax, if you use 3.x, please read the docs

And make the function in the Game script:

func _on_shape_player_spawned():
    # code to calculate sound volume
    $path_to_sound_node.play() #or whatever code you need to play the sound

If you are adding shapes via code, don't forget to connect the signal every time you add a new shape and incrementing a variable in your game script to keep track of their number (for sound manipulation).
If you are destroying a shape, it's good to disconnect the signal before that. And dont forget to decrement the variable.

Megalomaniak

LoveLearningGD However, when I use get_node() or $, there is no way for my Square to locate any nodes from my Game scene because it originates from a different scene.

No different scenes during runtime(just the SceneTree, while running your game from editor tab back into editor and check the remote SceneTree to see for yourself), unless you are referring to PackedScene which is a instantiable SceneTree branch saved to a file on disk.

DaveTheCoder

You could access Game from Shape/Square using Game's absolute path. There are examples here:
https://docs.godotengine.org/en/3.5/classes/class_node.html?#class-node-method-get-node

I don't what your scene tree looks like, so I can't be more specific.

If you're using Godot 3.5 or later, you can make Game a Scene Unique Node.
https://docs.godotengine.org/en/3.5/tutorials/scripting/scene_unique_nodes.html?#scene-unique-nodes

Then you can access it from Shape/Square as get_node("%Game").