The word occult comes from the Latin word occultus (clandestine, hidden, secret), referring to “knowledge of the hidden” or “hidden knowledge”.
The term occult sciences was used in 16th-century Europe to refer to astrology, alchemy, and natural magic, which today are considered pseudosciences. The term occultism emerged in 19th-century France, amongst figures such as Antoine Court de Gébelin. It came to be associated with various French esoteric groups connected to Éliphas Lévi and Papus, and in 1875 was introduced into the English language by the esotericist Helena Blavatsky.
Throughout the 20th century, the term was used idiosyncratically by a range of different authors, but by the 21st century was commonly employed – including by academic scholars of esotericism – to refer to a range of esoteric currents that developed in the mid-19th century and their descendants. Occultism is thus often used to categorise such esoteric traditions as Spiritualism, Theosophy, Anthroposophy, the Hermetic Order of the Golden Dawn, and New Age.
8 hours? No thanks.
From the slides they seem to do a decent job with the occult influences on the Nazis but you are better off reading Nicholas Goodrick-Clarke's books (which this likely drew heavily from), like The Occult Roots of Nazism.
They do a worse job with the Communist side because the links aren't really there.