I'm taking a group of kids through an adventure this year at their school's D&D club, and they're all getting the same Background, Anvil Adventurer. I'd like to add a History specialization in, where it can be a random choice of 6 features, or the players can pick one of their choosing. But I'm not really sure if this can be done with the current version of Beyond. The technology is definitely there, but I'm not sure they've ever made the function universal. Does anyone know how to add a skill with a specialization choice?

Here's what I want it to look like.

Skill Proficiencies: Choose a proficiency in either Medicine or Survival. You are also proficient in History, which includes one of the following specializations:
The Burning Night: you did your focus of study in the night that took your family and house away. 
Faerûn in the Modern Era: you know a great deal about the physical and social evolution of Toril. 
Beasts & Monsters of the Plains: you've done a great deal of studying about the monsters and beasts of this corner of Faerûn. <br>
The Story of Saleen: you collected a lot of the lore and myth of the great wizard Saleen, and learned about how to sort through it all. <br>
Treasures of Saleen: you know a lot about the legends of Saleen's great artifacts and the 300-year search to recover them. <br>
The War of the Shadow Elders: the research you did on the Shadow Elder War and how it shaped the city of Anvil and Faerûn gives you an insider's look at the echoes it has had on Toril and your life.

You should be able to add some extra text under the Skill Proficiencies text box, but it wouldn't show up on the sheet. I'd say the best way would be adding those options as Bonds, since those show up on the sheet and you can even roll for them.