when I couldn't easily find a file in a folder but wanted to see in which context it is, I had this trick:

1. Search for the file (with ctrl+F)
2. Right-click the appropriate result in the list
3. Click "Show item's location" (or however it's called)

Result: Nautilus exited search mode, put me in the right folder, and *selected the file* for me (scrolling to it if necessary).

This used to work until Nautilus 3.20, and I would love to have that feature back.