Behold! A guide explaining how to customize the look & feel of the Ubuntu MATE 18.04 Bionic Beaver desktop using the numerous built-in tools and features of the MATE desktop environment, including MATE Tweak, panel layouts, global menu, dock, HUD, Mutiny Unity-like configuration, other settings, and more. Have fun. https://www.dedoimedo.com/computers/ubuntu-mate-pimp.html Cheers, Mrk
Take a look at the linked cool tricks in MATE article (ocsmag), and you'll see an example there. Basically, sophisticated in-app search tool. Mrk