The APN-AMBR defines the total bit rate that is allowed for all non-GBR bearers associated with a specific APN. The APN-AMBR limits the total non-GBR traffic for an APN, independent of the number of PDN connections and non-GBR bearers that are opened for that APN. For example, if an operator provides an APN for Internet, the operator may then limit the total bandwidth for that APN.
Read more at: http://tech.queryhome.com/30184/gbr-mbr-apn-ambr-and-ue-ambr
APN-AMBR is per UE-PGW (and APN). The APN-AMBR is a parameter is provided by the PCRF to the PCEF per IP-CAN session. If a UE has 5 non-GBR bearers on the same APN, they will be limited by the APN-AMBR associated to this IP-CAN session.
And I don't have APN-AMBR or UR-AMBR sorry :(