The functionality accessible to you in an individual project will depend on your assigned permissions in the project.
If you are the owner of a project, i.e. you are the one who created the project, all functionality will be available to you.
If you are a collaborator, access to functionality is determined by the permissions given to you by the project owner. You can see your assigned permissions in the "Collaborators" window. If your permissions are restricted, you can only view and access data and functionality according to your permissions. For example, the dataset window will only be present in your workspace if you have permission to view data.
Only the project owner can add collaborators and assign permissions.