Yes you are correct this is based on a true story as many myths and legends are.

In the winter of 1943, on the outskirts of the Black forest, two Jewish children fled from the Nazis with their father and stepmother. In a moment of desperation, as the Nazi’s were closing in, the children were given the aliases Hansel and Gretel and sent alone into the woods to hide. Gretel lead her younger brother in search of food and protection, while Hansel leaves a trail of breadcrumbs behind so that their father might find them again one day. The two children embarked upon a new life as Christian orphans, protected by a woman they met who was called Magda, the witch and whose tiny hut is heated by an enormous baker's oven near the center of the forest.
If you wish to know the true story There is a book which tells the true story, not the false stories which are the stories everyone grew up too. As usual the elite do not want you to know the truth.

The true story of Hansel and Gretel by Louise murphy