Access an input file from vault template injector

I use Vault to retrieve some secrets that I put inside a configuration file. All works fine until this configuration gets bigger and I want it to be saved in sub configs in a folder. The issue is that those files can’t get imported using go templating used to fill passwords…

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: my-app
spec:
  ...
  template:
    metadata:
      annotations:
        vault.hashicorp.com/agent-init-first: "true"
        vault.hashicorp.com/agent-inject: "true"
        vault.hashicorp.com/secret-volume-path-my-config: "/my-path/etc"
        vault.hashicorp.com/agent-inject-file-my-config: "my-app.conf"
        vault.hashicorp.com/agent-inject-secret-my-config: secret/data/my-app/config
        vault.hashicorp.com/agent-inject-template-my-config: |
          {{- $file := .Files }}
          {{ .Files.Get "configurations/init.conf" }}
          {{- with secret "secret/data/my-app/config" -}}
          ...
          {{- end }}

The file configurations/init.conf for example doesn’t seem to be visible by the vault injector and so gets simply replaced by <no value> . Is there a way to make those files in configurations/* visible to vault injector maybe by mounting them somewhere?

I already tried extra-secret annotation, but this simply places the “secrets” inside custom directory in vault which I cannot access it from my template to edit them because I cannot use them without some variable replacement.