Helpo de LibreOffice 24.8
Select a slide and click >> or << to add or remove the slide from the list.
Adds an existing slide to the bottom of the Selected slides list. You need to select a slide in the Existing slides list before you can use this button.
Removes a slide from the Selected slides list. You need to choose a slide in the Selected slides list before you can use this button.
Displays the name of the custom slide show. If you want, you can enter a new name.
Lists all of the slides in the order in which they appear in the current document.
Lists all of the slides in the custom slide show. If you want, you can change the order of the list by dragging the slides up or down.