This is one of the best features of DirectorySpot. If you have access to more than one school or organization using DirectorySpot, just make sure you have used the same email address for all of them as your username. If so, then you will see a tab called "Directories" on your phone the DirectorySpot app. Just click on it to select the Directory you want to access.
If you do not see all of the Directories that you should have access to, just contact the administrator at the school or organization you are missing and ask them to check which email they have you set up with? If it is different, then ask them to add you with the correct email address.