You can import those files to specific folders within the shared library, just make sure you are positioned within that folder when importing those files by drag-and-drop or make sure to select the correct list if using the Add button:
3. Add articles from your personal library by selecting one or more and dragging them to the desired shared library:
You will be prompted to select whether you want PDFs included, as well as annotations and duplicates merged or not.
Once those references are in a shared library, all team members within it will have access to them.