Help with pluck and pick

[pkrishn6]

{{ $envDict := pick .Values.global .Values.global.env }}
{{ $chartDict := pick $.envDict .Chart.Name }}
{{ $imgDict := pick $.chartDict "image" }}
{{- define "app.release_labels" }}
app: {{ printf "%s-%s" .Release.Name .Chart.Name | trunc 63 }}
version: {{ .Chart.Version }}
release: {{ .Release.Name }}
{{- end }}
{{- define "app.full_name" -}}
{{- printf "%s-%s" .Release.Name .Chart.Name | trunc 63 -}}
{{- end -}}
{{- define "app.repository" -}}
{{- printf "%s" .imgDict.repository | trunc 63 -}}
{{- end -}}
{{- define "app.tag" -}}
{{- printf "%s" .imgDict.tag -}}
{{- end -}}
{{- define "app.replica_count" -}}
{{- printf "%s" $.chartDict.replicaCount-}}
{{- end -}}

I am getting an error: executing "app.replica_count" at <$.charDict.replicaCo...>: can't evaluate field replicaCount in type interface {}

I am using this as a helper file in my helm chart repo. The input file to this looks like this:

global:
env: "dev"
dev:
hello-world:
image:
repository: gcr.io/google-samples
tag: '1.0'
replicaCount: '1'
hello-kube:
image:
repository: gcr.io/google-samples
tag: '1.0'
replicaCount: '1'
stage:
hello-world:
image:
repository: gcr.io/google-samples
tag: '1.0'
replicaCount: '1'
hello-kube:
image:
repository: gcr.io/google-samples
tag: '1.0'
replicaCount: '1'

Can some one please help me with what I am doing wrong?..
Many thanks in advance.