I want to make a animation for a gameobject which have children gameobject!

I know we can make a animation by dragging the gameobject in key frame.I want to make a animation not only parent gameobject's position have changed but also children gameobject's position have changed.Now we want to drag children gameobject's postion in key frame,then the animation window have change to edit children gameobject's animation.How to edit a children gameobject's animation by dragging it?Because edit it value is inconvenient by artist.They want to dragging the children gameobject and make it's parent's animation. Thank you for your help!