Indeed I agree with Lois, this is far from intuitive. I must confess that after one year and a half of contribution to WikiTree on a quasi-daily basis, I've not yet found "natural" this "Find" menu. Or maybe I have tried it once or twice, but since the first results which are ads were occupying all my laptop screen, I gave up quickly without scrolling further down to find the "true" results.
Disclaimer #1 : Not being a digital native (far from it), and even if familiar with computers, known by colleagues for my capacity to ignore menus and buttons even if they are showing right in the middle of the screen.
Disclaimer #2 : My activity on WT is mainly contributing in a part of the Tree where almost nothing had been done before, so I rarely search for anything at all.