This has been a feature request for well over 10 years now. If anyone has a cross-platform working example of how to do this, please fire it my way.
<https://xojo.com/issue/17335>
<https://xojo.com/issue/23750>
I can only help for the macOS, sorry.
To get the macBS Toolbar Search Item, it’s also quite a bit of hassle, but it can be done with the code in the Ohanaware App Kit. I have it on my list to create a tutorial on how to do it. I’ll see if I can flesh that out over the next few days.