This is a replacement for Siemens Door Bin ("Kühlschrankeinsatz").
The siemens replacement part number is 359341 - which is no longer in production.
I own a KG36E05/02-V04 fridge. According to the documentation, the part also fits for the following models:
In order to make it printable on common 3D-printers, I have split up the part into 3 which can easily be put together (no screws, no glue required).