/u/RexReaver asked a similar question a few months ago but no one answered the part of the question I'm interested in.
When the Nazi regime rose to power how difficult was travelling across the Third Reich, namely into occupied areas? How easy would it be for a member of the party or an SS officer to travel from Germany to occupied Poland? Would regular trains be running between these areas? Or would officials rely on military transport?
Based on the accounts of escaping PoWs, there do seem to have been a reasonable number of checks on travel - particularly around railway stations and so on, and Police were encouraged to check out anyone who looked suspicious.
A functioning railway system was very important for the administration of the Reich and the occupied areas, and so yes there would be regular trains from Berlin to, say, Warsaw. My gut feeling - and someone with more knowledge in this area might tell me I'm wrong - is that ordinary civilians would need some special permission to travel into Poland or France, but could move around Germany relatively easily. PoWs often explained their bad (or total lack of) German speaking by pretending to be French migrant workers, of whom there were lots in Germany and who seem to have been able to move around relatively freely with the right paperwork.
In other words, two Frenchmen on a train to Hamburg with the right official papers saying they had a job there, not too much of a problem, though they might get a couple more questions asked. A German on the same train would have their Ausweis checked but as long as it was in order, they wouldn't be asked who they were and why they were travelling unless there was an alert on (escaped PoWs, for instance!).
Now, soldiers in uniform are a different matter entirely - the military ran troop trains and their own transport flights, so if an SS Officer on official business needed to get from Berlin to Paris, he'd probably cadge a lift on a Luftwaffe flight if there was one going. Troop trains were pretty much for moving masses of troops, and your SS man might be able to hitch a lift but it's unlikely he'd want to.
If your SS Officer could prove he was who he said he was, and was in uniform, he could probably go pretty much anywhere as far as civilian authorities were concerned, and indeed the Wehrmacht had very little power over the SS either, but if a more senior SS Officer questioned him , he might need to prove he was legit.
If I can piggy back off of this question:
Currently the stigma of a police state is portrayed as a lot police checkpoints. Was this true traveling through Germany, where you were asked for your papers in order to go anywhere?