By default, the Motion Mixer expects that a mix you create will affect the entire non-biped object. If you like, you can Filtering Mixer Tracks a trackgroup so clips in the mix affect only selected body parts. This functionality makes it easy for you to assign one set of XAF files to control the motion of an object's upper body, while another set controls the lower body.
For more information and procedures on the use of trackgroup filters, see Filtering Mixer Tracks.

Display is on, which it is by default). Objects can be individually activated or deactivated by clicking them, or you can use the buttons across the bottom of the Trackgroup Filter diagram to expedite selections.When on, highlighting an object automatically select all its children.