It depends on the power of the transmitted signal, and your proximity to it.
If the signal is quite strong without the gain of a Yagi, you could insert an attenuator in line with the yagi, or detune it antenna matcher adjusted for weaker signal response rather than for increased signal response. Or, if you select dimensions for a Yagi slightly out of the band, you still get the directional nature of the antenna with a bit less gain. Go higher rather than lower if you go outside of the band. This will allow you to use the scanner with a Yagi for direction finding.
You might want to do some general searches for "Fox hunt", "Foxhunting", "Projects", etc, and combinations of these. There have been a number of projects published in QST also. You might find one suitable for what you need.
:Will a yagi antenna "fry" my scanner? I would like to find a this type of antenna to pinpoint direction of 2 way radio transmissions. Any ideas?