You can combine a pattern overlay in Photoshop by selecting a shape layer etc and then adding a pattern overlay via the layer styles menu and then by going to the layer menu and convert smart object and then going back to the layer menu and layer styles and pattern overlay. Change the blending modes etc and re-position the different patterns. You can repeat this over and over. Some have more than two pattern overlays and some also mix a few effects to smear the results. Here are a few examples below using the patterns from graphicxtras.com
By Andrew Buckle. Photoshop custom shapes, Illustrator symbols, plug-ins, brushes, styles, picture tubes, gradients and many more for Photoshop and Photoshop Elements and Affinity Photo, Affinity Designer, Krita, Paint Shop Pro and Painter.. as well as fonts, patterns, textures etc for many others. Programming as well as designs and arts and scrap booking and a little more