* Words: This is the main noun of the sentence, as it's the subject being discussed.
* Sentence: This is another noun, referring to the collection of words we are examining.
* Group: This is also a noun, describing the way the words are arranged.
* Nouns: This is the final noun in the sentence, as it's the type of word we're looking for.
So the nouns in the sentence are: words, sentence, group, and nouns.
However, the sentence itself is grammatically incorrect. It should be: "The words in this sentence group that are funny are nouns."