If you're the Owner, an Admin, or an Editor, you can make a copy of a styleguide in the workspace by hovering over a styleguide’s thumbnail and selecting “Make a copy…” under the Settings menu.
You can select to include users in the copy. The duplicated styleguide will automatically include all screens and resources in the local styleguide.
☝️If you're copying a child styleguide, duplicated styleguide will be linked to the same parent styleguide. If you're copying a parent styleguide, duplicated styleguide will not be linked same child styleguides.