If you want to use the BBBike extract service, you have to choose the desired area.
How to use the BBBike extract service:
1. Go to
http://extract.bbbike.org/?lang=en2. Move the map to your desired location.
3. Choose "Manually select a different area"
4. Message "Drag a box on the map to select an area" shows up.
5. Click and hold the left mouse button, draw the bounding box, release the left mouse button.
6. Enter "Format: Osmand (OBF)", "Your email address" and "Name of area to extract"
7. Push the "extract" button.
8. Wait for email notification and download the map.
Regards,
Max