I'm specifically asking about the very elite officers of the Wehrmacht. Generals in high positions in the OKW like Jodl, Generals and Field Marshals at Army Group etc positions like Rommel, Manstein, Model or von Rundstedt.
Today we know that The Battle of Stalingrad and the Battle of Kursk were turning points in the east but that was not neccessarily clear for people at that time, was it? So I guess it should be sometimes between Kursk and Bagration/Overlord, but is there actual proof, like for example Generals confronting Hitler for the first time about the senselessness of the fight?
It seems so that the Party elite (Goebbels, Göring, Himmler and Hitler himself) never really acted on that until the very end, so I don't want to count those in.
The German army more or less collapsed as a unified fighting force in March 1945, when the western allies broke through over the Rhine on a broad front with well-supplied and fresh troops. Before that, the Soviets had conducted their Vistula-Oder offensive in January-February 1945, which saw them enter German soil, capture Königsberg (the old capital of East Prussia) and push the Germans away from the encirkled city of Budapest, which the Germans had tried repeatedly to relieve the siege of.
Before this series of events, the Germans had stabilised the front in the west in October 1944 and turned back a Soviet offensive to advance in Poland and against East Prussia. While the Soviets crushed Romania and liberated the Balkans, the Germans stemmed the tide against Poland and East Prussia for several months between late August 1944 and mid-January 1945.
The Soviets had outun their supply and had problems continuing their advance, as had the western allies in France after operation Market-Garden and the fighting at Metz and in the Hurtgen forest.
This gave new hope to the Germans, who gathered for the Ardennes Offensive (the Battle of the Bulge) and attempted to relieve Budapest in several offensives.
Up until March 1945, many Germans still clinged to the vain hope that they would be able to stop the Soviets and negotiate a peace agreement with the western allies, who would then join them in fighting back the Soviets.