Hello.
Base on the documentation:
"Important: On a BIG-IP® system that includes both Local Traffic Manager™ (LTM®) and Global Traffic Manager™ (now BIG-IP ®DNS), all IP addresses that BIG-IP DNS references (virtual IP addresses, link addresses, and so on) must be associated with route domain 0."
REF - https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos-routing-administration-12-0-0/9.html
You can use route domains in different LTM devices using this
REF - https://techdocs.f5.com/kb/en-us/products/big-ip-dns/manuals/product/bigip-dns-implementations-13-0-0/11.html
KR,
Dario.