From the Workspace window, you can Control-click on any document and choose Copy Link to copy a link to the document in a Workspace to your clipboard.
In an open document, click on the three dots in the Collaboration menu in the toolbar and choose Copy Link to copy a link to the document in your Workspace to your clipboard.
Tip: You can find both Copy Link and Manage Share Settings… in the menu bar under File > Workspace as well.
Click on the Share button in the About tab or the three dots icon and select Share…. From here, you can invite other people via email to edit or view your document — as well as defining what people with a link to your document can do.