So morality is merely a tool for biological advancement?
And is therefore just a matter or expediency and not a statement of absolute good or bad.
So again, with that in mind, what did Hitler do wrong?
What does the society that rapes and pillages another society do wrong?
They are not doing anything wrong, according to your expressed worldview, they are just acting expediently.
In this age of information sharing , morality is well defined by a worldwide set of definitions.
Long ago this was not possible , so morality was regional, or even dictated locally. In the end morality is defined by the consensus within a group. What the accepted terms of morality are, depends on the group defining them. So absolute morality would be what was decided by the largest set of people. But there could never be a true absolute morality, not as long as two sets exist.