These sorts of issues occurred in many places beyond just Northern Ireland.
In Ontario, for example, these kinds of hiring discrimination against catholics used to be prevalent generations ago. The same existed in other parts of Canada. It wasn’t really that long ago when there was a taboo against catholics and protestants marrying each other in Ontario. I’ve gone trhough a lot of archived newspapers in Ontario from the 19th century, and the attitude against catholics is sometimes striking. My favourite example from what I’ve seen, was a minor political scandal that erupted sometime in the 1890s (I forget the exact details) when a politician running for a seat in East Toronto had his reputation smeared when his opponents accused him of being a catholic, and newspaper editors aligned with his party came to his defence by insisting he was a presbyterian and that he was also a good man.
When the British empire existed, for a long time, catholics were denied equal rights under the law and discrimination against catholics was widespread in many colonies (as well as in the UK itself). When the British conquered French Canada during the Seven Year War (1756-1763), for a while the British were even entertaining the thought of having a legislative assembly for Quebec that worked according to the same anti-catholic rules as existed in Britain at the time (wherein catholics could neither cast a vote or hold office), which would have effectively meant that the very tiny protestant minority in Quebec at the time (perhaps less than 1000 protestants in a larger colonial population of maybe up to 100,000 catholics) would have ruled over everyone else. This, however, was an idea that got shot down when the British decided to give an exemption and let catholics in Quebec have some political rights.
In Lutheran parts of Germany there were many anti-catholic laws and discriminatory practices.
However, catholics were not just victims in this though, because I think catholic countries often had similar discrimination against protestants. Prior to the revolution of 1789, I think France may have enforced laws in discrimination against religious minorities, for example.
In Holland, where the country is split between catholics and protestants, there are ridiculous stories of discrimination that you can hear even from older dutch people still alive today about how a catholic would not hire a protestant because he was a protestant and vice-versa, protestants did not buy bread from catholic bakers because the catholics had made the bread and vice-versa, etc.
I’m not surprised if there are parts of the world that this kind of thing is still existent though.
I suspect similar issues exist, although perhaps not openly, about people who would not be hired because they are atheists or people who are not hired because they are religious, etc.
The world largely seems to have changed though:
72. This is true above all for the European countries, in which these divisions first appeared, and for North America. In this regard, without wishing to minimize the other visits, I would especially mention those within Europe which took me twice to Germany, in November 1980 and in April-May 1987; to the United Kingdom (England, Scotland and Wales) in May-June 1982; to Switzerland in June 1984; and to the Scandinavian and Nordic countries (Finland, Sweden, Norway, Denmark and Iceland) in June 1989. In an atmosphere of joy, mutual respect, Christian solidarity and prayer I met so very many brothers and sisters, all making a committed effort to be faithful to the Gospel. Seeing all this has been for me a great source of encouragement. We experienced the Lord's presence among us.
In this respect I would like to mention one demonstration dictated by fraternal charity and marked by deep clarity of faith which made a profound impression on me. I am speaking of the Eucharistic celebrations at which I presided in Finland and Sweden during my journey to the Scandinavian and Nordic countries. At Communion time, the Lutheran Bishops approached the celebrant. They wished, by means of an agreed gesture, to demonstrate their desire for that time when we, Catholics and Lutherans, will be able to share the same Eucharist, and they wished to receive the celebrant's blessing. With love I blessed them. The same gesture, so rich in meaning, was repeated in Rome at the Mass at which I presided in Piazza Farnese, on the sixth centenary of the canonization of Saint Birgitta of Sweden, on 6 October 1991.
I have encountered similar sentiments on the other side of the ocean also: in Canada, in September 1984; and particularly in September 1987 in the United States, where one notices a great ecumenical openness. This was the case, to give one example, of the ecumenical meeting held at Columbia, South Carolina on 11 September 1987. The very fact that such meetings regularly take place between the Pope and these brothers and sisters whose Churches and Ecclesial Communities originate in the Reformation is important in itself. I am deeply grateful for the warm reception which I have received both from the leaders of the various Communities and from the Communities as a whole. From this standpoint, I consider significant the ecumenical celebration of the Word held in Columbia on the theme of the family.
–John Paul II, Ut Unum Sint, 1995
When JPII addrsseed the European parliament, Ian Paisely (the northern Irish protestant leader) was present and he made a big scene and shouted out that JPII was the antichrist. He was removed from the room.
Thank you for your OP,