iTunes home sharing videos with iOS 10.2 TV app
The TV app will show all iTunes libraries that are shared under the same Home Sharing account right on the "front page"

When you start the app, you should be on the "Library" tab (check tab at bottom, you have "Library", "Watch Now", "Store" and "Search").

Your home sharing libraries will be listed on the Library page, you have  "TV Shows", "Movies" and then the name of your library, with the name you picked in iTunes' General Preferences, Library Name. If you have more than one iTunes instance running on your network, and they're all shared on the same account, they will all show up there.