In Openshift 3.11 we used "ingress.bluemix.net/rewrite-path" annotation for rewrite. Now we have migrated to 4.3 version of Openshift in which Many annotations are not supported from 3.11. We have api and ui applications. So we keep host same and just add path /aps-ui/ and /aps-api/.This is the requirement of our applications.
As I know, the feature is developing at the moment here : https://github.com/openshift/router/pull/129
haproxy.router.openshift.io/rewrite-target
And it will be added to the OCP4.z in the future. I believe it'll be soon.