Choose Hide Object List when you want to close the list.
In the slide navigator, Control-click one of the selected objects, then choose Group from the shortcut menu.
Lock or unlock a group: Click the lock icon on the right side of the group name.
Show or hide the objects in a group: Click the disclosure arrow next to the group name.
Add an object to a group: Drag the object between two objects in the group. You can also copy and paste an object from another open presentation or drag an image or other object from a web browser or from your computer.
Remove an object from a group: Drag the object above the group name or below and to the left of the group.
Ungroup objects: Control-click the group, then choose Ungroup from the shortcut menu.
For more information, see Layer, group, and lock objects in Keynote on Mac