<p>I want to print a part from Thingiverse. In the description, the creater writes that he used SBS to print it. I did some research because I never heard of SBS.
I found a description on Filaments.directory that describes it as:</p>
<blockquote>
<p>Poly(styrene-butadiene-styrene) is a hard, durable rubber that is commonly used for shoe soles, tires and other products that experience high wear.</p>
</blockquote>
<p>But if I search for SBS filaments to buy, there only shows ABS up. Did I misunderstood something and SBS  is the same as ABS.</p>

As you found and according to this site, SBS is a
Styryne-Butadiene
polymer that only contains Styrene and Butadiene chains interlinked. This is similar to ABS, but not identical.
Some people have access to filament manufacturing machines or use pellet extruders, however, googling for
"SBS" filament
I was able to source at the moment two sites with information:
Craftbot.nl
is a reseller who also explain why this stuff is such expensive with 40€ for 750 grams
the
very site you had (apparently defunct, no waybackmachine grab)
, which tells us there is exactly one brand:
Filamentarno
from Russia, but the link to the amazon marketplace from there shows no availability of this product at all.