For safety sake, damaged seat rail means get a new saddle. That saddle is probably OEM for Focus; meaning it may not be
commercial avaialble. Perhaps your LBS can contact Focus per an identical replacement. Many saddle manufacturers will make saddles for bike companies re-branded with their bike company logos + model names. that saddle has the shape of a
Selle Italia one. Most saddles that come with the bike a relatively inexpensive; people to tend to change out seats, pedals,
& handlebars to what is more comfortable for them.

Not only may rail dimensions be important to you - but also length and width of saddle in milimeters. Clamps of the seat post can sometimes be changed out to accomodate a saddle with larger rails. If that is not the case you could always purchase another seat post that has larger clamps.