Menus > Animation > Create > New selection handle

Animation > Create > New selection handle

Create selection handles to distinguish parts of a model.

See Add selection handles

See Use selection handles to make picking easier

Once selected they can be applied to a new layer for later use.

When you pick a selection handle, all other items that are not attached to the selection handle become unpicked.
If you drag over part of an object that has a selection handle, the object is not picked unless you drag over the selection handle itself.

In the SBD window, you can pick any node, whether or not it has a selection handle.