The directory tree in Project Manager is managed in the PRO.DLP file. This is located in folder C:\ProgramData\Dlubal\Global\Project Manager by default. You can check the directory paths of Project Manager in the "Program Options" dialog box (click Project Manager menu "Edit → Program Options"); see also Image 01.
This database file is available to all users. If each user should use a different project structure, you can create a PRO.DLP for each user (for example, PRO_User1.DLP, PRO_User2.DLP). The relevant database file must then be set by the respective user in the program options after each change of a user. This is also shown in the video.