You can have the show-template at the container level as well.
Take a look at the example: examples.confd/cli/show_templates
Regarding values, you can only show them the way they are shown in an auto-rendered output.
But if you want to be free to show whatever format you like, I recommend creation an all operational view of the configuration and register data callbacks to show the output.
You can then control exactly how you want to display the values. In your range case, you can model the leaf as a string and either show integer values, or ranges. Your data provider has to know what it needs to return as a value in this case.