Within the MediaStorm platform, all instances where there is a link URL via a field in the tool are able to accept absolute (full) URLs as well as relative URLs. A relative URL is a URL that only includes the path. The path is everything that comes after the domain, including the directory and slug. This is used for linking items within your release to other areas of the same release.
The example below shows both versions of the same URL linked within a button on a release. Both options work, but if you are creating internal links and pathways inside your release, it makes sense to simplify it.
Absolute:
Relative: