A workaround is use patch port to connect multiple virtual bridges:
ifcfg-virbr0
DEVICE=virbr0 DEVICETYPE=ovs TYPE=OVSBridge ONBOOT=yes BOOTPROTO=none NM_CONTROLLED=no DELAY=0 HOTPLUG=no
ifcfg-virbr1
DEVICE=virbr1 DEVICETYPE=ovs TYPE=OVSBridge ONBOOT=yes BOOTPROTO=none NM_CONTROLLED=no DELAY=0 HOTPLUG=no
ifcfg-patch1-0
DEVICE=patch1-0 ONBOOT=yes DEVICETYPE=ovs TYPE=OVSPatchPort OVS_BRIDGE=virbr1 OVS_PATCH_PEER=patch0-1
ifcfg-patch0-1
DEVICE=patch0-1 ONBOOT=yes DEVICETYPE=ovs TYPE=OVSPatchPort OVS_BRIDGE=virbr0 OVS_PATCH_PEER=patch1-0
Maximun patch port is 5
ovs-vsctl show Bridge "virbr0" Port "virbr0" Interface "virbr0" type: internal Port "patch0-1" Interface "patch0-1" type: patch options: Bridge "virbr1" Port "bond0" Interface "eth0" Interface "eth1" Port "patch1-0" Interface "patch1-0" type: patch options: Port "virbr1" Interface "virbr1" type: internal