From the Capella Project Explorer, select Import…

In the dialog box, select “Existing Projects into Workspace”.

Then, “select archive file” if the project you want to import is a zip, or “root directory” if it is not.

When choosing “Select archive file”, the following dialog box opens:

The archive of the Project will be extracted inside the Workspace (i.e. the physical location of the imported will be the same as the location of the Workspace).
When choosing “Select Root Directory”, the following dialog box opens:

For each project in the selected directory, one can select whether the Project should be copied within the Workspace or not.
When choosing the copy option:
Click on Finish. The selected projects are opened in the current workspace.