small bug here:

When pressing the "Select bones shown in the dopesheet" button:

• the bones are added to a selection
• the bones are not highlighted/selected in the tree view (bug?)
• any previous selection in the tree view remains/is not cleared (bug?)

By contrast, when clicking on a bone's name/row in the dopesheet:

• the bone is added to a selection
• the bone is highlighted/selected in the tree view
• any previous selection in the tree view is cleared and replaced by the new selection