If you are searching for the Analytics on the left-side Powerbar, make sure that you are not on the Cover Page. Analytics are only available on the Style Guide Documents and not the Cover Page.
Click on another item in the top Navigation from the Style Guide and check if the Analytics appear now.
If you are searching for the Overview Brand Analytics Dashboard, only Account Admins are able to view the dashboard Analytics by clicking on the avatar > “Analytics”. You can find more information here: Analytics ( Enterprise only)