There are two similar laminated doughs, but recipes make them slightly different, but overall what are the main differences between brioche feuilletee and croissant dough?
They are very similar, here is the difference according to The Bread Bible by Rose Levy Beranbaum:
Croissant and brioche have the same ingredients: flour, yeast, salt, sugar, milk, and butter. There are only two significant differences: croissant dough contains almost double the amount of butter and has only milk as the liquid component, whereas the liquid for brioche dough comes mostly from eggs, with only a little milk. The eggs in the brioche dough give it an airy cake-like crumb, while the large amount of butter in the croissant dough, and the way in which it is rolled and layered into the dough, gives it its flaky crumb.