Hi Angela
Good question ??
Meta Slider doesn’t by default offer layering. Ultra has a little Meta Slider functionality added that allows the main image to be moved to the background and an overlay image to added via its URL to the caption field in Meta Slider. It’s a little advanced but doable. We do our best to cover this technique in full here: https://purothemes.com/documentation/ultra-theme/meta-slider/.
Of course, the SiteOrigin Slider widget, part of the SiteOrigin Widgets Bundle and Master Slider offer layering for free. If you’d like to use one of these options I can assist in getting the slider into the same position that Meta Slider gets inserted into.