Starting from the two fields you describe:
You can obtain the text of either field through its ".text" attribute. The "split" operator breaks a string on the right at instances of the string on the left and produces a list. Splitting one string on spaces gets us part of the way to what you're asking for. We can then use the comma operator to join a pair of lists.
" " split field1.text
The best way to experiment with this sort of thing is to use The Listener. Ask a "question", get an answer:
Another approach for gathering space-separated words from several fields would be to use an "each" loop:
Does that help point you in the right direction?