From the dashboard, create a folder by clicking the ‘+’ menu in the top right corner of the Workspaces panel. Select ‘Folder’. When the ‘Create Folder’ window pops up, enter a name and hit ‘Save’.
Right click on the menu to the right of the Workspace name and select ‘Move To’. Select the desired folder and hit ‘Move here’. You can also move Folders inside each other by following the same process.
Right now, folders are used strictly for project organization, not user permissions.