In the Activity Sheet overlay page, you can use the Open Project in <source name> option (see System Activity Sheet) to open the Oracle Primavera Cloud page and open the source URL either in P6 or Oracle Primavera Cloud, in a new tab. The Activities tab points to the relevant project data (the project that is selected in the drop-down provided there is an active login session).
The login on the new tab for P6 or Oracle Primavera Cloud will be displayed where you ender your login credentials to sign in and see the relevant project data.
Note: You can see the project is opened even when that particular project is closed in the source server.
Selecting this icon will open the source application in a new tab provided there is a valid URL specified. If no URL is defined in the company properties page, then this link will not be shown in the Activity Sheet.
Also, when you switch to Baseline, the link is not displayed.