Question: is it possible to use managed resource result in go-template?

### What happened?

I'm pretty new to use `go-templating-function` for composition. What I want to achieve is to pass result of provisioned managed resource to another managed resource in compostion. Let's say I want to create AWS security group and security group rule associated with group I created like:

```yaml
{{- $xr := .observed.composite.resource }}
apiVersion: ec2.aws.upbound.io/v1beta1
kind: SecurityGroup
metadata:
name: security-group
annotations:
crossplane.io/composition-resource-name: security-group
spec:
forProvider:
region: {{ $xr.spec.region }}
vpcId: {{ $xr.spec.vpcId }}
name: {{ $xr.spec.name }}-security-group

apiVersion: ec2.aws.upbound.io/v1beta1
kind: SecurityGroupRule
metadata:
name: security-group-rule
annotations:
crossplane.io/composition-resource-name: security-group-rule
spec:
forProvider:
region: {{ $xr.spec.region }}
fromPort: {{ $xr.spec.fromPort}}
toPort: {{ $xr.spec.toPort}}
protocol: TCP
type: ingress
securityGroupId: ???
```

so, I just want to use security group id created by security group in security group rule. If I use patch way, normally I can use `ToCompositeFieldPath` patch in security group resource to write security group id to XR , then use `FromCompositeFieldPath` patch in security group rule resource to read security group id from XR.

But I don't know how to achieve that in go-templating function?

### How can we reproduce it?

No need

### What environment did it happen in?
Function version: v0.4.1

Review the go-templating function's handling of `.observed` resources and the documented composition patch flow, using the supplied SecurityGroup and SecurityGroupRule manifests as the reproduction. Done should be a clear, version-specific answer or an actionable requirement with a documented way to pass the observed security-group ID.

Written by the indexing model from the issue text.