This is a pretty good example of this problem which got a top of front page hit for my google search (and it's been viewed 15k+ times):

https://stackoverflow.com/questions/36747293/how-to-specify-...

The question is tagged for ASP.NET Core 1.0 so there's answers that are applicable to that version. Then things changed in 2.1, which removes some friction when adding custom view locations, and another user posted an answer specifically for that version.