Simple example how to project position from another layer using LayerToCanvas and CanvasToLayer expressions.
Setting Sprite position from "UI" layer (parallax 0,0) to Player Sprite in "level" layer (parallax 100,100)
Set X position
CanvasToLayerX("UI",LayerToCanvasX("level", Player.x, Player.y) ,LayerToCanvasY("level", Player.x, Player.y))
CanvasToLayerY("UI",LayerToCanvasX("level", Player.x, Player.y) ,LayerToCanvasY("level", Player.x, Player.y))
Simple example file attached.