Getting service, namespace of matched rule in accessLog

*Description*:
i have a use case such that in my dashboards i use namespace and service name to filter my traffic
now in envoy i want to add a field to my access log as below
```
UPS: _
```
how can i achieve it?
currently the solution i'm using is creating HTTPRoute for every service
```
UPS: %CEL(xds.route_metadata.filter_metadata['envoy-gateway']['resources'][0]['namespace'])%_%CEL(xds.route_metadata.filter_metadata['envoy-gateway']['resources'][0]['name'])%
```