Did you see what your employer sent in answer to the questionnaire? Did he not give full answers?
As the CO is asking for this, that is what the employer needs to send. The CO will be looking at the ANZSCO description of your job, and wanting to know that you carry out responsibilities to match all, or nearly all, the lines on that description. For instance, if you were a chef, you would need to look at this page
http://www.abs.gov.au/ausstats/abs@....OUP+3513+Chefs, at the part under 'Tasks include', and for each line the employer would need to write what you actually DO, day by day and week by week, which matches that line. For the first one, it might say something like, 'Mr AKG talks to our suppliers of meat, fish and vegetables every Monday, asking about the availability and price of fresh products for the week ahead, and he then plans the items for the specials board accordingly, keeping in mind the overall budget available per serving.' If the CO wants more evidence of that than just the fact that your employer says so, you would have to get letters from the suppliers to say that it happens. I don't know what you actually do for a living, so you will need to look at your own job's ANZSCO page and work out from that what you can agree with your boss that he will write.