GitLab: Open active file on GitLab - workspace path not filtered out
https://gitlab.com/fatihacet/gitlab-vscode-extension/blob/master/src/openers.js#L51
that at least for me seems not to work (Win 10 1709 64bit)
Url is containing full path; perhaps this helps:
https://github.com/jakob101/RelativePath/blob/master/src/extension.ts#L84