Thank you for asking this question in the support community forum. One way to view the interface bandwidth is to use the statistics rate-interval 30 command, and then issue the show interfaces command. This will provide 30 second snapshots of the interface bandwidth. If you would like to monitor it long term, then Integrated Traffic Monitoring (ITM) may be the best way. Please review the Configuring Integrated Traffic Monitoring (ITM) in AOS guide for information on how to configure ITM.
Please, do not hesitate to reply to this post with any additional questions, I will be happy to help in any way I can.