Select the layer or layer group you want to duplicate.
Open the Duplicate panel in the Craft toolbar.
Select whether you’d like to duplicate the layer vertically, horizontally, or both, then enter the number of times you’d like to duplicate that layer. You can also use the slider bars or the gutter fields to specify the spacing.
Click Duplicate Content.
If you select an element and then click Duplicate Content, a new layer called “Duplicate control” gets created and selected. If you drag the corner or side anchors to resize that, the original layer will be duplicated enough times to fill the newly resized duplicate control layer.
If you have your gutter set really high, then you might not see additional copies. You can use the sliders beneath the "Gutter" fields to adjust the spacing between the duplicated elements and the changes will be reflected live within the document.
If the layers you’re duplicating were previously filled by Craft (using the Data tool), you’ll get a fresh set of content for every item created. That makes it quick and easy to fill spaces with sample data that looks real.