Use metadata(branch name) in templates

Is it possible to use metadata, like variables for branchnames when creating a template for merge requests?

As an example, I want a template that contains a link to a certain website, depending on the source branch of the merge request: http://myurl.asdf.com/BRANCHNAME/somesubstuff

Can I do that? If yes, the documentation should be updated, since I didn’t find anything about that topic.