You can have a dashboard like GNOME Shell on Xfce, take a look at this:

xfdashboard
http://goodies.xfce.org/projects/applications/xfdashboard/start

It’s a dashboard like GNOME’s “Activities” that is at the top left corner of the screen. This can replace your menu if you wish, it search apps, you can customize it with Xdashboard settings, change the theme, use some plugins. I was not able to use the “hot corner” plugin(that feature that you move the cursor to the corner of the screen and the dashboard opens) , but you can launch the way you want it, for example put it on the panel or elsewhere, or launch it with a Keyboard shortcut and you will have a GNOME Shell like dashboard. Video from 2015 showing some features.