You can find tests on dynamically specifying the View and Template in TemplateViewPagesTests.
The View Pages can be in any folder in the /Views folder with the format {PageName}.html where PageName can be either the Request DTO Name, Response DTO Name or HttpResult.View property if returning a custom HttpResult. All page names need to be unique in the /Views folder.
One difference from Razor is that it uses a cascading _layout.html instead of /Views/Shared/_Layout.cshtml. So if your view page was in:
/Views/dir/MyRequest.html
It will use the closest _layout.html it can find starting from: