What I'm really asking is: How could this be possible when The Allies were closing in on the western front, while the Soviets were closing in on the eastern front? One of the first things we are told in this movie, is that the Soviets were 12 kilometers from the center of Berlin. The only logical thing to do, would be to flee north through the port of either Mecklenburg or Lübeck, which I can assume were blockaded by The Royal Navy. Were they just planning on hiding under a rock till the smoke cleared?
The movie begins on April 20th.
As late as the 23rd there was access to aircraft, as Hitler's personal staff was ordered to leave and flew to Salzberg. Most of Austria was not yet occupied.
There were other later breakout attempts that did head north to either reach the western allies or reach the surviving members of the German army. Martin Bormann got as far as the river, but Mohnke made it about 4 km further north when the city surrendered.
It was probably not the situation to make long term plans beyond surviving the day.
Is it possible that by "escape" they meant escape the Russians and surrender to the West?
Many high-ranking Nazis tried escaping by disguising their identity and hiding in the masses of POWs that were moving all over Europe at the end of the war. This included false names, papers and uniforms.
To name a few examples, concentration camp doctor Josef Mengele spent several weeks in a US run POW internment camp, but was released without being recognized. Adolf Eichmann also managed to escape using a false name and rank. Heinrich Himmler was arrested by the British, but after a few days in captivity his disguise was broken, whereupon he committed suicide.
None of these men, however, were in Berlin around the time the city was conquered. Discounting the problem of keeping up a false identity, getting out of the city alive in the midst of intense battle was difficult by itself after the last airplane (carrying pilot Hanna Reitsch and Field Marshal von Greim under orders of the Führer) had left on April 28th. Actual escapes by high-ranking Nazis in the bunker were out of the question as long as Hitler was alive. By the time Hitler killed himself on April 30th the bunker was surrounded by Soviet troups, but the next day several people took their chances regardless, although most were either killed (Bormann, Stumpfegger) or captured (Baur, Mohnke). At least one man, Hitler youth leader Arthur Axmann made it out and managed to live in Germany under a false identity for half a year until he was arrested.
So to summarize, the idea was to escape by hiding in the chaos using a false identity and then leaving the country quietly, which offered decent chances for success. For those who remained in the bunker with Hitler the odds were much worse, but not entirely impossible.