Yes, you certainly can do it. Here is how:
Tools > Options... > Theater View
Select Video under "Items to show", click Add... > Library Item. Click Set rules for file display...
One rule you need: Media Type is TV
Add more rules (optional): TV Tuner Input Type is DVB-T etc.
Use Nest/Unnest button to put it under Video, or as a root item.
The attached image shows three items that I added as an illustration. One as root item, "tv all channels", two under Video, "TV Channels" (which I should have named "Digital Channels", since I set input type to all digital types, i.e. ATSC, DVB-T, QAM, etc.) and "STB Channels" (for my stb and analog cable channels).