Hello David
Internal QoS groups are a feature of Cisco QoS that allows a device to assign an internal label to identify packets as members of a specific class. The distinctive characteristic of these QoS groups is that the label is not part of the packet header itself, and it is only locally significant, that is, only the device on which QoS groups are configured takes these QoS groups into account. QoS groups essentially provide a way to tag a packet for subsequent QoS action locally on the device, without explicitly marking or changing the packet.
Note that a QoS group is identified and applied to the packet at ingress and is used at egress. It is assigned in an input policy to identify packets in an output policy.
For more info, take a look at this Cisco documentation:
Nested policy maps in Cisco QoS are a way to implement more granular and hierarchical QoS policies. They allow the configuration of a policy within another policy, enabling advanced QoS features such as hierarchical queueing.
The diagram you shared shows an example of nested policy maps:
Parent Policy Map: This policy map is the one that is applied to the interface Gi1 in the egress direction. The PARENT-POLICY is the top-level policy map that is directly associated with the interface.
Class-Default: Within the PARENT-POLICY, the class-default class map is specified, which typically matches all traffic not matched by any other class map. A child policy map named CHILD-POLICY is attached to this class.
Child Policy Map: The CHILD-POLICY is nested within the PARENT-POLICY. This child policy map has its own traffic classes, in this case, VOIP-TELEPHONY, and specific actions assigned to it, such as priority percent 35, which indicates that 35% of the available bandwidth is allocated to VoIP telephony traffic.
Arguably the most important aspect of these nested policies is that the child policy’s bandwidth allocation is a portion of the bandwidth assigned to the parent policy, not the total bandwidth of the interface. In a hierarchical QoS structure, the parent policy controls the overall bandwidth allocation to its child policies. The percentages assigned in child policies are a fraction of the bandwidth that the parent policy has at its disposal, which may be less than the total interface bandwidth due to other policies or limitations set at the parent level.
In the example you shared, it looks like all of the bandwidth is available to the parent policy, so the percentage is indeed that of the total interface bandwidth.
Take a look at this Cisco documentation for more information:
I hope this has been helpful!
Laz