The image of a German military or police officer barking 'Papieren!' wile clad in Nazi-era uniform with a complimentary German Shepherd on a leash is more an artistic trope, popularized by numerous war movies rather than a phenomenon specifically tied with Nazi Germany. You can say with a high decree of accuracy that it was pretty common fare with modern bureaucratic systems, especially those associated with police states, but to a large extent it is true in modern world.

Now, the aforementioned situation, when an uniformed Nazi officer asks for 'papers', especially in a condescending, demanding manner would have been quite common in the areas occupied by Germany during the war, especially in the areas that were effectively annexed or planned to be incorporated into Germany (General Governorate, or the eastern part of Poland bordering with the Soviet zone before June 1941). In these regions, many measures were taken to subject non-Germans to various limitations and impose control over the conquered people. And thus, said officer could have asked for papers to check, whether a person met during a curfew has a business of being there (e.g. returning from late shift at work), is not a wanted criminal (what included known members of resistance an their sympathizers) or is not a Jew or Romani that were persecuted for their ethnic background alone. In Germany, a policeman could have asked for papers to make sure a person drinking in a regular pub and speaking with a suspicious accent is not a forced labourer (who were not allowed to use many facilities not specifically designated for them).

Last but not least, there were the 'raids' (also referred by the terms like 'razzia', 'rafle' or 'łapanka') conducted by various services (police, SS, Sonderdienst, Gestapo, military) in the occupied areas, especially in Central and Eastern Europe. They were usually conducted by a quick cordoning off a specific place and rounding up all the people present there with an exception of residents, customers of the businesses etc. Then, all people who were not considered necessary for the local economy (primarily workers of the factories crucial for war effort, transport, health service etc.) were often arrested and transported off to Germany as 'forced labour'. Those exposed as wanted people or those with no documents also faced imprisonment or labour camp. Members of the intelligentsia, especially high-ranking officials, professors (pre-war documents often included the 'learned occupation') or priests could have also faced summary execution because of so-called Intelligenzaktion,a genocidal practice aimed at physical elimination of the intellectual elites of the conquered nations.

The documents in question could have been dependent on the situation. Usually these were personal IDs issued by the local government or any other form of identification (passports, workers ID), more or less corresponding to what one would consider ID nowadays. In occupied Poland, since 26th October 1939, all citizen over 15th years of age were issued to have a Identification Card (ger. Kennkarte) issued by the occupational government (and since 13th June 1941 they were obliged to have one). It is conjectured that this measure was introduced to counteract the mass production of falsified documents (they often were not even counterfeit, as many of such documents were clandestinely issued by the officials helping their compatriots, and were completely legitimate even though they contained false data). It goes without saying that the Kennkarten were falsified no less eagerly. According to the conjectures of Gestapo and estimates of the Land Army HQ, roughly 10% of the adult citizens of General Governorate used falsified or counterfeit documents.

Another important document was the Work Card (ger. Arbeitskarte), essentially a small booklet that contained all the information concerning the bearer's occupation history and the Workplace ID (ger. Beschaftigungsnachweis) that contained detail concerning one's employment, such as the position held, type of employment and the insurance fees paid. As mentioned previously, relative safety of the citizen was related to their occupation stated in the documents (real or fictional). Those employed in the factories and companies directly tied to the German war effort (weapons and ammunition factories, food processing plants, pharmaceutical companies) were quite safe from being arrested or sent to forced labour outside their place of residence. Even safer were specialists employed by the providers of communication and transport services such as railway (to lesser extent also tram and bus networks), post office and telephone or telegraph, as these people were considered crucial to a smooth running of the country and were generally left alone. Construction specialists were also relatively safe for the same reasons. On the other hand, possession of the Permission Card (ger. Erlaubnisskarte) also granted relative immunity from persecution with this document being issued to various artists, chiefly orchestra musicians and stage actors who, due to the specifics of their occupation, were often required to travel around the country. In addition, a member ID of a fishing organization was considered 'good' as German occupants, recognizing an importance of fisheries as a food for troops, were also not eager to harass fishers (this also extended to peasants, although these were largely not used to papers and often did not have any, but the chances of being asked for papers in rural, sparsely populated areas were slim, if any).

In addition, gendarme or policeman could have also asked for any relevant papers. For example, all motorist and even cyclists needed to have the registration papers of the vehicle they used (especially given that most vehicles were usually confiscated by the occupant and thus a motorist was expected to have documents permitting the use of a motor vehicle, such as e.g. proof that they are employed in a capacity of a driver). Motorists would have also needed a driver's license (in 1930s it was uncommon, but far from unheard of to drive without any formal documents). Other documents could have included various workplace passes stating that a given person is allowed to leave their workplace at will because of their duties (this was common in occupied areas and people working during the curfew hours, usually at night).

Of course, in any restricted areas, such as military zones, high-security factories or even checkpoints set up to hinder people in occupied areas from moving freely, guards were asking for a pass or other documents that would identify them as people who are indeed allowed entry such as a pass, workplace ID (ger. Ausweis) etc.

So, to sum it up, the demand for showing one's papers was not a practice specific to Nazi Germany, but given that the Germany conquered quite a substantial part of Europe, the measures employed to control local population propelled uniformed services to enact far stricter and more numerous methods of enforcing the rules what corresponded to far more frequent document check in comparison to the same areas prior to the war.