config.yaml

#@ load("@ytt:data", "data")
#@ load("@ytt:template", "template")

#@yaml/text-templated-strings
#@ val1 = "port:(@=  str(data.values.service.port) @)"
#@ val2 = "val2"
---
apiVersion: v1
kind: ConfigMap
metadata:
  name:  myconfig
data:       
  zzz0: "port:(@=  str(data.values.service.port) @)"
  zzz1: #@ val1 

values.yaml

#@data/values
---
service:  
  namespace: benoit
  name: dogs
  port: 8080