See for yourself, what is running in your HA instance. 
Go to Developer Tools > Template and paste this instead of the demo code:
All domains used:
- {{ states|map(attribute='domain')|unique|list|join('\n- ') }}
Or all available entities:
- {{ states|selectattr('state', 'ne', 'unavailable')|map(attribute='entity_id')|list|join('\n- ') }}
Shamelessly copied from here
You will likely don’t need to choose from a list of domains, as these are mostly determined by the integration you want to install. From your example, you get something offered from your UPS integration, in your case sensors. Eg. you can’t change yourself what the integration provides, so you can’t make a binary_sensor out of a sensor provided by an integration. There are ways to work around this (hint: template sensors), but that is beyond the scope of this topic here.
On a sidenote, if you want to dig deeper inside these things, I’d recommend to install Spook. It’s from Frenck, one of the main developers of HA. There you can get some more statistic values about entities. You can get it via HACS just search for Spook. The docu is here. But this is unrelated to your config questions, it is just a recommendation in general for statistic fans.
PS: Bookmark this post, you’ll likely need that domain command when you take a look at your history and database sizes in the near future. 
See here.