I came across this weird compound preposition recently so had a dig around to find out what it’s all about. It seems to be something like “towards” or “in relation to”.
In the examples given here:
1. Ele foi muito mal-educado para comigo. He was very rude about me
2. Não tenho qualquer rancor para com ele. I don’t have any rancour towards him
3. Pode ser ser que eles o tenham sido para contigo, mas para mim sempre foram irrepreensíveis. They might have been [like that] towards you but to me they’ve always been irreproachable
4. Para com os seus pares, ele mostrou-se à altura. This seems to be incorrect as far as I can tell from reading the text.