We all love simplicity, yet we also love freedom of choice. Sometimes these two parameters can be at odds with each other. For instance, if I go out for a beer I'm not too happy if there's only one b...
Updated Apr 25, 2019
Version 1.0
Blog Post
Yes, it is possible to return multiple claims from a Function. As long as it's in json and you have defined the claims in the base policy it's achievable. Depending on how you set things up you may need to use a JSON transformation:
https://docs.microsoft.com/en-us/azure/active-directory-b2c/json-transformations
Hiding and showing UI elements is a possibility when enabling JS and supplying "standard" JS for manipulating the DOM:
https://docs.microsoft.com/en-us/azure/active-directory-b2c/javascript-and-page-layout?pivots=b2c-user-flow
However, my real world experience is that this might be more hassle than you like it to be. Sure, I tried it in my lab and it worked. But the thing is that B2C provides JS you don't control so you have to do things retroactively in your JS and that can take some time working out. A frontend dev will be able to handle it, but make sure you really want it before doing it.
To be honest I'm not entirely sure which of these approaches I would recommend if I were to implement things today. Moving the logic inside B2C makes things very friendly for the client side development. On the other hand having the client handle domain hints in the query string is easier the other way around 
