How to create a wp site that allows users to create groups

Hello All,

I've got a potential client with a specific request and I'm thinking about using Wordpress for the job. I'm going to try to explain the functionality reqeusted as best as possible and hope that someone can help or point me in the right direction of completing this using Wordpress.

Company X has employees that each handle y number of clients. What Co. X would like is for all employees to be able to have a system where they can upload/download documents for each client, the client can submit docs and submit a form that tracks work time and location, and employees can download reports. They would also like all docs stored online, so clients can see what docs were submitted and when, delete, etc.

I was thinking of using the Membership plugin but not sure if this would work since each employee needs to create they're own group. Also, each client would need to create a login profile.

Does anyone know how to go about doing this? Are there any WP themes, frameworks, plugins that could be used for this? I'm a beginner at PHP/MySQL so creating something like this on my own might be too advanced for me. I appreciate any feedback, thank you!