Thule comes from a Greek cartographer, Pytheas. Thule was supposed to be an island to the north of Britain, but nobody knows what he referred to or if whatever place he referred to even was real. Some people, especially 19th century Scandinavian nationalists, associate Thule with Scandinavia.

There seems to be multiple Thule, but none of them in Sweden: https://en.wikipedia.org/wiki/Thule_(disambiguation), although there seems to be a Swedish brand with the name as well, but unrelated to the location as far as I can tell https://en.wikipedia.org/wiki/Thule_Group

Multiple I think. I believe Thule was the capital of the Greenland Norse civilization, but it's also a local story about a high culture that disappeared.