How did the Germans address Hitler?

by saying mein fuhrer, heres an example:

Hitler- wer bist Sie? (who are they)

you- mein fuhrer, das ist der dritte heeres gruppe.

(my leader, that is the 3th army group)

in the example you are speaking as like a nazi general or aide to Hitler but everyone called him mein fuhrer when adressing him or when speaking about him but not adressing them they would say Der Fuhrer
Hitler was addressed as "Fuhrer", meaning Leader.