Collision only detects parent collider ?

Unity Engine
1

Hi all~~ I have a character , on the character it self I have added a box collider and a Rigidbody component.
And then on the each of the character’s biped hand , I have each added a box collider as well.
Now, I have change the tag on the hand collider to “PlayerAttack”, and the collider on the body as untagged.
When I run the game, I keep getting Untagged as retrun result when I test it with a script.
Does collision only detectcts on top level ?

2

Child colliders are used to make compound colliders, that act as a single collider.

–Eric