There have been a fair few questions asked before that may interest you whilst you wait for a more specific to your question:
In our FAQ we have a subsection of our "Nazi Germany in WWII" section devoted to civilian knowledge of the Holocaust during the war.
Also in our FAQ there are a few questions on the process of "Denazification" (elimination of Nazi influence on German & Austrian society outlined in the Potsdam agreement)
"What did the German people know or understand about the Nazi concentration camps during WWII?" - asked 20th July 2012
"Was your average Nazi aware of and complicit in the atrocities of the Nazi regime?" - asked 2nd January 2013
"During WW2, how did the German civilian population respond when reports from the concentration camps hit the common people?" - asked 20th July 2013
"How much did the German citizens know about the concentration/extermination camps during WWII?" - asked 30th August 2015
Hopefully this helps, as the threads I've listed are archived if you have any questions for users that have answered these questions just ping their username with your question & hopefully they'll get back to you :)
Firstly, I assume you are on about the episode where they see the mass graves in the camp
The nazis kept this quiet for most of the war. State media attempted to privatise the entire thing so even the local population didn't know what was going on. Most Germans merely thought Hitler was arresting those he hated. People abroad expected there to be some form of mass detainment for those Hitler hated, but they never expected things like Auschwitz, so when they found it, it was naturally quite a shock to the system as they hadn't known about one of the biggest violations of human rights