AI strafe animations

I need to play animations on strafing AI depending on where it’s facing. I didn’t find any good info on internet. And of course AI doesn’t use any input.
Exactly what I need: I need to determine when I should play left-right strafe animations if transform is moving right-left in it’s relative space(basically to determine if forward is on X or Z). I know there is method Transform.TransformDirection but I don’t quite understand how to use it. Picture related.

https://gamedev.stackexchange.com/questions/43897/determining-if-something-is-on-the-right-or-left-side-of-an-object?fbclid=IwAR0u7f0REHZBYAYqcgoV5CGNXeWzoNgu9T-hE31C3lWBKuEmUl7Sd-mVcRo