When a part has been selected to be drawn in 2D, a window will be displayed. This window has two tabs at the bottom: Parts List and 2D Machining Tools. The Parts List will show all the parts that belong to the parent of the selected part. This could be the main product or a subassembly.
By selecting a part and then right-clicking, you can draw the part in 2D or update the product with the current changes that were made to the selected part.