module I18n::Backend::Flatten

def normalize_flat_keys(locale, key, scope, separator)

and then resolve_links.
Shortcut to I18n::Backend::Flatten.normalize_flat_keys 
def normalize_flat_keys(locale, key, scope, separator)
  key = I18n::Backend::Flatten.normalize_flat_keys(locale, key, scope, separator)
  resolve_link(locale, key)
end