Disk Expert allows you to collect files in a special list to further manage them. You can copy, move or remove selected files and folders. There is a special panel for selected items.

To add files to this collection you can drop items right from the diagram or select files in the Biggest files panel.

Then you can manage the selected items by clicking to remove them or copying or moving them to any desired folder.
When you click to move or copy files, the app will display the Finder window where you can select the new location. Choose a new folder and click the Select button.

If you click to remove selected items, they will be physically moved to Trash.
Also, you can use the Menu Bar to operate selected items.