How to separate multiple values of an attribute

I have an attribute that has multiple values, I would like to separate them

Currently when I add the attribute it looks like this

Attribute: one two three

when I would like it to look like

Attribute One
Two
Three

I tried using <br/> in between them but no luck

How do I separate or is it not possible? Thank you

Hello James,

The value of attribute is entered via a text input. You can not use break line tag in it.

Sincerely, Giang