It cannot be set in UI.
Use the /rawconfig command-line parameter:
https://winscp.net/eng/docs/rawconfig

Thanks - but I couldn't find a way to set those settings in the preferences for the UI.

Use Interface\SessionTabNameFormat raw configuration setting:
https://winscp.net/eng/docs/rawconfig#interface_sessiontabnameformat

Hi - I've tried those options but it didn't have any effect. I'm attaching a screenshot of the path I'm referring to.

Where exactly do you want to "View Site name without full path"?
Are you looking for this?
https://winscp.net/eng/docs/ui_pref_window#path_title

Hello,
Is there a way to view the active connection/site names with the site name only, excluding the folder path?
Thanks,
Christine