Why is というのは used (both times) in this sentence?


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?

> その場面というのはどういった場面かというと、  
>  ナチスの兵士がですね、ユダヤ人を職業別で分けていきます。  
>  役に立つと見なされた職業というのはブルーカード、  
>  役に立たないと見なされた職業というのは即ゲットー行きです。

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




というのは is a fixed phrase.

  * と: the quotative particle which is used with いう
  * いう: "say"
  * の: the nominalizer (turns a verb into a noun)
  * は: the topic marker

So literally, ○○というのは is something like "saying ○○ is ..."

というのは can be used in two ways.

  1. というのは used alone at the beginning of a sentence is a conjunctional phrase, which means "I mean", "That is to say", "I'm saying this because", etc. In this case, と refers to what the speaker said in the previous sentence.
  2. ○○というのは is a fixed pattern used when the speaker wants to explain the characteristics of something, or to define something. You can think of it as a special emphatic topic marker. It's often interchangeable with [○○とは](https://japanese.stackexchange.com/q/19310/5010), which is another important particle combination used to give a definition. 

> 人生というのは長い旅だ。 ≒ 人生とは長い旅だ。 ≒ Life is a long journey.

In your example,
その場面というのは[どういった](https://japanese.stackexchange.com/q/33536/5010)場面か is
basically the same as その場面はどういった場面か. And it forms a noun phrase ([embedded
question](https://japanese.stackexchange.com/a/13038/5010)) which means "What
kind of scene that scene is".

> その場面というのはどういった場面かというと、  
>  ≒ 「その場面はどういった場面か」というと、  
>  ≒ (lit.) When I say "what kind of scene that scene is", ...  
>  ≒ To explain that scene in details, ... / The scene I'm talking about is
> ...

(と)いうと after the embedded question here is another very common pattern which
roughly means "To tell/say ...", "Speaking of...", etc.

>   * 本当のことを言うと、… To tell the truth, ...
>   * なぜかと言うと、… To explain why, ... / The reason why is ...
>   * 率直に言うと、… Frankly speaking, ... / To be honest, ...
>

