Power BI Web App User Access Permissions

My company is beginning to use our Power BI premium workspace. As of now I am the serving admin dealing with user acess and report creation. To help with user acceptance I decided to publish the premium workspace as an app using the top right button. I created a file structure that would be easy to navigate and would help seperate out reports for users to be able to use and understand easily. The problem I see coming relatively soon is that we wouldn't want Employee A who works in accounting to see everything we are doing within sales. Not only because some data may be sensitive from employee to employee but we also do not want the left panel of the app interface eventually getting bogged down with so many reports that when a user logs on they see it as a hassle to get to their report. Is there a way to limit what a user can see and access within the premium workspace to limit what would pop up for them within the Power BI app on the web?