Document exporting nested subgroups

modules/gdscript/doc_classes/@GDScript.xml

@@ -666,7 +666,19 @@
 				@export var car_label = "Speedy"
 				@export var car_number = 3
 				[/codeblock]
-				[b]Note:[/b] Subgroups cannot be nested, they only provide one extra level of depth. Just like the next group ends the previous group, so do the subsequent subgroups.
+				[b]Note:[/b] Subgroups cannot be nested, but you can use the slash separator ([code]/[/code]) to achieve the desired effect:
+				[codeblock]
+				@export_group("Car Properties")
+				@export_subgroup("Wheels", "wheel_")
+				@export_subgroup("Wheels/Front", "front_wheel_")
+				@export var front_wheel_strength = 10
+				@export var front_wheel_mobility = 5
+				@export_subgroup("Wheels/Rear", "rear_wheel_")
+				@export var rear_wheel_strength = 8
+				@export var rear_wheel_mobility = 3
+				@export_subgroup("Wheels", "wheel_")
+				@export var wheel_material: PhysicsMaterial
+				[/codeblock]
 			</description>
 		</annotation>
 		<annotation name="@export_tool_button">