Corporate video management

Hello expert! My name is Mathew. I am creating a corporate video content management system. Basically it will work like a multisite network and when employees will login to the web portal, it should appear some what like Vimeo or YouTube. The access level to videos will differ from department to department. The website should be responsive for smartphones and iPads, so that the higher authorities should be able to access the content on their phones and tablets. Kindly help me in building this portal.