Batch selection is a great way to perform several actions at once, such as deleting multiple assets following a specific broadcast. This is all done from the main Switcher Studio screen's Sources Menu.
At the bottom-right of the Sources Menu is a Select option. Tap on Select.
Little circles will appear in the bottom-right of each thumbnail in the Sources Menu.
Tap on the assets that you would like to select to place a blue checkmark in those assets' thumbnails.
You can now manage these assets. The delete icon in the bottom-left corner of the screen allows you to mass-delete assets. The stacked icon next to it allows you to mass-duplicate assets.