the file manager is still available. It is under the insert toolbar.
Go to Window -> Insert to open the insert toolbar. In the insert toolbar, select WebAssist then the File manager icon.
you can use either the file manager or file manipulation - file upload for what you are asking about.
The File manager offers a way of browsing files that are already on the server for selection or for uploading.
the file upload behavior only allows for uploading.
which to use really depends on the feature set you wish to offer the website user.