[Moo] Selectors in a class using "contains"

[rpflo]

this.contentElements is a bunch of <li>s in a class.
keyArray is whatever words are in an input field.

trying to do a basic filter.

This works:

keyArray.each(function(word){
     $$('#list li:contains("'+word+'")').removeClass('hidden');
}.bind(this));

This does not, but I'd really like it to :)

keyArray.each(function(word){
     $$(this.contentElements+':contains("'+word+'")').removeClass
('hidden');
}.bind(this));

Obviously my selector is wrong, any ideas?  Thank you!