There is a video available for this process at this link.
SVEditor provides a wizard for creating new filelists. The wizard can be invoked from the main menu (File>New>SystemVerilog Filelist) if the SystemVerilog perspective is active or from File>New>Other>SVEditor>SystemVerilog Filelist.
The wizard can also be invoked from the context menu when a container (folder or project) is selected.
At this point you will see the first dialog in the wizard as shown. In this dialog you will specify the name, as well as the location for the argument file. Check the Add to Project Settings to include the argument file in the current project.
The dialog to select files for the argument files will then appear. Select files or directories to be included and hit Compute Filelist. The contents of the file will be previewed. Once you are satisfied hit Finish.
The Organize Files switch causes the wizard to process the selected files and eliminate included files and add +incdir+ paths. This can be very helpful, especially with SystemVerilog testbench environments, in creating a correct filelist. When Organize Files is not checked, all selected SystemVerilog files are added to the file list.
The new filelist will be displayed in the editor window. A file header is pre-pended to the file. The header can be found in the preferences section at Window>Preferences>SVEditor>SV Template Properties.