The N-panel in the Close Bone Picker Editor provides various operators and features for registering hierarchy structures.
Pick Real Bone
Selects the bone assigned to the selected node in the 3D View.
Pick Parent / Child Pick Brother
Performs the same operations as described in

Auto Add from Selection
Batch imports bones selected in the 3D View into the Node Tree. If they are connected in the actual hierarchy structure, they will be automatically linked upon import.

Copy Node
Copies the selected node to the clipboard.
Paste Node
Recreates node information from the clipboard into the Node Tree. While standard Ctrl+C/V also works for copying and pasting, using these operators allows you to copy and paste even when opening multiple Blender instances or switching between different blend files.

Replace
Renames nodes based on the From/To information provided. Particularly useful for bone structures with identical left/right symmetry.

Send selectd structure to Armature
Sends the hierarchy structure connected to the selected Bone Node(s) to the active Armature. You don't need to select all Bone Nodes—selecting any one of them is sufficient.
Send Piemenu to Armature
Select a Pie Menu node and execute to send the connected Pie Menu node information to the active Armature. Unlike the above command, the Pie Menu node itself must be selected.
Restore from Armature
Recreates the hierarchy structure currently saved in the object within the Node Tree. This becomes available when an object with a saved hierarchy structure is active, and the number of nodes to be restored is displayed below the button.

Export / Import Template
Exports all selected node information to a JSON file of your choice. Importing that file recreates the node information in the Node Tree.
