For a far more comprehensive and insightful answer to your question, read They Thought They Were Free by Milton Mayer. This slim volume and Sebastian Haffner's The Meaning of Hitler may be the two most underappreciated contributions to the study of National Socialist Germany.
A Cliff's Notes answer, while unsatisfactory, would be to say that National Socialism (Nazism to us Yanks, and not to be confused with the Fascism of Mussolini's Italy or Franco's Spain) could not be isolated to any one class. I assume “class” is what you meant by “levels” in the OP. Disenfranchised laborers shared a party affiliation with the directors of multinational corporations. Lower and middle classes swelled the ranks of the SA while industrialists like Krupp and Porsche funneled huge amounts of liquid cash into Nazi campaign funds. It is illustrative that the marchers in the failed 1923 Nazi putsch included Hitler (a failed Austrian artist), Ludendorff (the de facto head of the German state in the last months of the Great War), Göring (an upper-class morphine-addicted flying ace), and Himmler (a university-educated chicken farmer).
If any generalization could be made, it is that those who were better educated and socially liberal were less inclined to support the National Socialists, but even here a couple caveats apply:
First, see Mayer's work for the story of the school teacher (an elevated and highly respected profession in pre-war Germany) who admitted that National Socialism led to the erasure of class distinctions--he was “accepted by his inferiors”—which he found appealing.
Second, (see Haffner for this) had Hitler died in the Autumn of 1938, even his most ardent critics would have admitted that he would go down next to Bismark and Frederick in the pantheon of great German statesmen. The ensuing war and Holocaust color our perception of Hitler and National Socialism far more than the incredible success of his first five years (not an apologia--just an observation).
The genius of Hitler was to combine the conservative appeal of nationalism with “socialism” (the scare quotes are intentional) to poach support from Social Democrats and Communists, both of which had significant influence in interwar Germany.Â
