thanks for the response, im using the first methid and working andd i got new problem.
so i'm using the code to make sort of a popup inventory menu, then i make variable that detect player mouse click and area detection for the inventory icon.
so when both variable are true, the inventory came out.
but the problem is whenever i click the item, the menu closes.
i figured that i have to use the second method but i dont quite get it.

im trying to get the area2D variable which detect mouse collision on menu area and it worked on it's own scene.
but not when i connect it from main menu scene.
get_tree().get_root().get_node("root/path/to/node").variable.
i have no idea what to write on get_node path.