GTM Topology

I use topology records to make the GTM decide if it needs to hand out internal IPs (to internal clients) or external IPs (to external clients) for one specific service. I do this by defining two topology records that verify if the source of the LDNS request is "172.16.0.0/12," make the destination "INTERNAL-POOL." If the LDNS source is anything else, make the destination "EXTERNAL-POOL"

This has worked well up until now. Now, we have other applications on the GTM that need to do the same type of thing. We also need topology rules for other services that send users to different datacenters based on their LDNS request source. Since my first two topology records referenced in the first paragraph are specific to one service/pool, I'm not sure how to proceed. I could use weights to make the INTERNAL/EXTERNAL rules a higher priority and then the new rules for Datacenter selection could go under them. But, what if I need to have the GTM decide rather to hand out internal/external IPs for a NEW service. This wouldn't be possible since the two toplogy records are specific to one pool/service.

Ideally, the toplogy rules would allow you to specify a LDNS Request Hostname and let you create rules based on that, but it does not.

Any ideas would be greatly appreciated. My apologies for a somewhat confusing explanation and question.

Thanks!