How do I drag a bone from a 3D model onto my custom component?

I created a custom component with a public GameObject property, with the intention of this property’s value being a bone in an animated character.

However, when I press the selector icon to the right of the property field, in the list of available assets, no where do I see a bone. I only see the 3D animated character model.

What am I doing wrong?

Figured it out by clicking on the 3D asset in the Inspector view, then the Configure button and the bone transforms were automatically exposed.