Create two lease pools. One for 10.10.10.0/24 (i.e. lease-pool-us) and one for 10.10.20.0/24 (lease-pool-uk). Then create two Network Access resources, one for us, one for uk and use the corresponding lease pool in it.
then create a visual policy with different paths for different AD groups, in the one path do the Network Access assignment for us and in the other do the uk assignment.
You can also set the ADQuery agent with a single "Successful" branch (configured with the expression "AD Query has passed") and leverage the AD Group Resource Assign agent: https://techdocs.f5.com/en-us/bigip-15-1-0/big-ip-access-policy-manager-visual-policy-editor/access-...