You can create and use multiple VM-VM affinity rules, however, this might lead to situations where the rules conflict with one another.
If two VM-VM affinity rules are in conflict, you cannot activate both. For example, if one rule keeps two virtual machines together and another rule keeps the same two virtual machines apart, you cannot activate both rules. Select one of the rules to apply and deactivate or remove the conflicting rule.
When two VM-VM affinity rules conflict, the older one takes precedence and the newer rule is deactivated. DRS only tries to satisfy activated rules and deactivated rules are ignored. DRS gives higher precedence to preventing violations of anti-affinity rules than violations of affinity rules.