Create a pipinine CodeStar that spans two different AWS accounts

For the same project, I have two separate accounts a dev

and an account staging/production

.

First, every developer has full access to all of the account's services. There's a CodeStar service in there, when the corresponding CodeCommit is clicked, the Pipeline starts up and continues until the code itself is deployed. When the development team is fine with their work, they can fork the mainline to mark the release ready for stage / production.

When a new release needs a milestone, the business must choose which branch it wants to deploy in the milestone. So, with one code, the click should be retrieved from the first account created and deployed to that staging account (the last one).

• How can I do something like this?
• How do I run an intermediate pipeline from a CodeCommit source to another account?
• I would use CodeStar on the latest account (so I can use the toolbar), right? Or should I start with a custom workflow?

Any suggestion given is appreciated, I haven't seen any best practice on the internet.