When attaching a file to an email, how to limit search to a selected folder

I'm using TB 157.0.1 on a Mac. When I want to attach a file to an email, I click on Shift+Cmd+A. I want to be able to navigate to a folder where the file is, then search for the file by name within the folder I navigated to. But it doesn't quite work that way. I navigate to the folder, enter the file name in the search field, hit Return, and TB searches my entire hard drive. How can I force TB to limit the search to the folder I navigated to? When I hit Return (or Enter) and TB searches the entire hard drive, the window that displays search results has a field I can click on that will limit the search to the folder I navigated to, but I'd like to eliminate that extra step. I'd like to set a default when searching for a file to attach so that search is limited to the folder I navigated to. Is that possible?