In order to demonstrate your proficiency, use the link to the partner site
Evaluation (top right-hand corner of your site navigation bar) to find the Google form for your Product and Level (both sites are identical in order to facilitate navigation). There, you will find a list of tasks you would need to be able to fulfill in order to achieve that level. You would need to submit evidence of your ability to complete these tasks (this can take the form of screenshots, videocasting, or any other format you see fit).