I'm trying to understand the use of というのは in the second sentence below. Is it a way to refer to the 職業 in the first sentence? I find in some places that というのは can mean "the reason I'm saying this is..." Is that the meaning expressed in this example? For example, people are given a blue card (because) they have a useful profession?
Translation from subtitles: "The scene I'm talking about is the one with the Nazi soldiers separating Jewish people by profession. They give a blue card to people who are considered with an useful job. People who are considered with an unuseful job are sent to the ghetto immediately."
Source: https://www.youtube.com/watch?v=3xs-XWk_oQA 0:55