The two righteousness are our own and the other one is Christ's righteousness. They have their purposes and it is important that we know the difference.
We have our own righteousness and that usually make us feel good but does not save us. While Christ's righteousness is what saves us.
Relying on our own righteousness makes the death of Jesus Christ on the cross meaningless. Does that mean that our own righteousness have no use ? Our own righteousness as i understand comes after we are save.
We are save when we rely or believe in Christ's rightousness.