Himmler, not Hitler

According to most rational sources, Hitler wasn't interested in the occult: mistrusted it, even. Himmler was the one with mystic leanings.

In connection with the SS (1929), Himmler set up the Ahnenerb (name changes in bureaucracy, but this is the most common name) in 1935, to find the evidence that Nordics had ruled the world and set up all civilizations worth the name.

They were absorbed into the general SS at the start of 1939. They backed research into extant pagan sorcerers of Finland, the excavations at Viking Age Hedeby and the Mauern caves, recording the Bohuslän petroglyphs of Sweden, Camunic runes in Italy (Romans were Nordic!), doing anthropology in Tibet (Buddha was Nordic & his philosophy was so close to Hitler's!). They helped loot Poland, & tried to get Gothic remains out of the Crimea (Red Army beat them).

They planned but cancelled expeditions to Bolivia (Andean megalithic structures are Nordic!), Iran (Behistun inscription), the Canary Islands, & Iceland.

The Ahnenerb set up a portion of Master Plan East. They meant to give their Nordic colonists from South Tyrol and northern Ukraine a "natural setting" of beech and oak forests outside Kiev, while having them grow new crops from Tibet.

Their experimental scientists conducted fatal research on prisoners at Dachau & made a collection of Jewish skeletons & skulls by murdering the sources, picked out live.

Nothing glamourous, huh?

That's because the stuff of legend is fiction. Conspiracy theorists & thriller writers are responsible for it. Nicholas Goodrick-Clarke analyzed the "Modern Mythology of Nazi Occultism" in The Occult Roots of Nazism

"There is a persistent idea, widely canvassed in a sensational genre of literature, that the Nazis were principally inspired and directed by occult agencies from 1920 to 1945".

These works "were typically sensational and under-researched. A complete ignorance of the primary sources was common to most authors and inaccuracies and wild claims were repeated by each newcomer to the genre until an abundant literature existed, based on wholly spurious 'facts' concerning the powerful Thule Society, the Nazi links with the East, and Hitler's occult initiation."

The Morning of the Magicians (1960) and The Spear of Destiny (1972) especially helped promote the idea that the Nazis started as an occult group, in the Thule Society (which Hitler never joined though quite a few Nazis came out of Thule). The earliest claim for an occult base was in Lewis Spence's Occult Causes of the Present War (1940).

As for any Vril Society, that never existed or managed to leave no trace.

So we can't tell you what you ask. Your assumption of Hitler's interest, searches and all are based in non-historical fantasies. It's like asking for details of when and where Abe Lincoln went vampire hunting.

So I can't recommend any further reading, either. I avoid that stuff like I avoid ancient aliens.