Well my undersatanding is before Vatican 2 it was true that the catholic church claimed itself as the only church whereby one could be saved...that apart from the catholic church people were damned. But Vatican 2 changed that????
No, it did not change that, it has come to a deeper understanding of what is the church. That has happened within the church where an existing belief or accepted theology is expanded and clarified, but not changed.
The Church acknowledges that anyone baptized in the name of the Father, Son and Holy Spirit are members of the church, though separated by schism.
I believe the Catechism can do a much better job of explaining, but haven’t the time now to post what it says.