there is no short answer to this 
service tags exist but have never had any function, there is a long discussion about whether they can be deprecated at Deprecation of the Service Tags feature
so a really functioning drop-down tag group feature for services: I’d say no.
But I’m not sure what you are trying to accomplish. Would you mind explaining the original problem, maybe there is a completely different solution that is possible. (see What is the XY problem? - Meta Stack Exchange )