You can load a .tscn dynamically by doing this:
var path = "res://somwehere/scene.tscn"
# Instance as child:
var scene_resource = load(path)
var scene = scene_resource.instance()
# Or, load as complete replacement of current scene:
Note: I see your path contains "SAVES", I hope you don't use this folder to write savegame player data, because "res://" is not writable for exported games. Instead, savegames should be put under "user://".