All of the Precepts of Socialism are based on community.
The Bolsheviks and Mensheviks, indeed all the Socialist partys, believed in the dictatorship of the "workers and peasants" where all would live in peace and harmony, from each, according to their ability, to each, according to their need.
In order to achieve this utopia, the "class enemy" must be fought and defeated and the instruments of oppression (bourgoiuse captialist government) overthrown in a revolutionary mass movement. In Bolshevik terms, that revolution is to be led by the "vanguard", the elightened activists.
The National Socialists beleived in the racial community of all Germans, an Aryan volksgemeineshaft. They were opposed to and fought the existing bourgeouise government, which was viewed as a tool of the racial enemy, and as such the National Socialists were revolutionary.
Both philosophies were revolutionary. Revolution is a tool of the left.
Both philosphies had enemies. The Bolsheviks, for example, had the bourgeoise and capitalists. The National Socialists, had the Jews.
Both philosophies were similar economicaly. Socialism entails the State the owning the means of production. National Socialism was hybrid, private ownership under the direction of the state for the benefit of the state was permitted, and the government owned other economic concerns (viz, the SS economic empire).
Both philosophies were "mass movements". Everything was to be a benefit to either the "people" or the "volk"
The very fact of their revolutionary nature demonstrates that National Socialism is left wing.
The fact that National Socialists are also Socialists is amply demonstrated by the foregoing.
Socialism in all its forms mandates mass murder because of its disregard of human nature.