How to dynamically get ARN, and also compose multiple component yml files together?

[Suedo]

Currently, I am creating a Role for a DynamoDB table that i defined elsewhere using the component aws-dynamodb.
In my aws-iam-role yml file, I am defining the Dynamo DB Resource as:

      Resource:
        - arn:aws:dynamodb:${env:AWS_REGION}:*:table/backend-db-${env.STAGE}
        - arn:aws:dynamodb:${env:AWS_REGION}:*:table/backend-db-${env.STAGE}/index/*

I just found out that we can't use plugins, but how about CLoudformation !REF or !GetAtt to make things more dynamic?

Also, how do I compose multiple serverless-component's yml files together as one ? My basic serverless express project's tree looks like this at the moment:

.
├── ./app.js
├── ./package.json
├── ./permissions
│   └── ./permissions/serverless.yml
├── ./resources
│   └── ./resources/serverless.yml
├── ./serverless.yml
├── ./src
│   ├── ./src/handlers.ts
│   └── ./src/index.ts
├── ./tsconfig.json
└── ./yarn.lock

As you can see, I have multiple serverless.yml files for each of the components I am using (express, IAM, DynamoDB) . How do I compose these together?