The following example enables traffic shaping for all traffic on the outside interface, and prioritizes traffic within VPN tunnel-grp1 with the DSCP bit set to ef:
hostname(config)# class-map TG1-voice
hostname(config-cmap)# match tunnel-group tunnel-grp1
hostname(config-cmap)# match dscp ef
hostname(config)# policy-map priority-sub-policy
hostname(config-pmap)# class TG1-voice
hostname(config-pmap-c)# priority
hostname(config-pmap-c)# policy-map shape_policy
hostname(config-pmap)# class class-default
hostname(config-pmap-c)# shape
hostname(config-pmap-c)# service-policy priority-sub-policy
hostname(config-pmap-c)# service-policy shape_policy interface outside