There is a couple of ways, depending on whether you want to run the network scanner interactively or not.
If you want to use the GUI, you can simply create multiple configuration files, say one file for each location. Each configuration file can define subnets specific to that location as well as any other settings, e.g. user credentials. So when you are on site A, you can load configuration A. On site B, you load configuration B and so on. This can be done in the main menu via
File - Current Config - Save/Load.
If you don't want to use the GUI and want to run from a script, there is a number of supported command line switches. Specifically the ones you may want to use are
/auto,
/config and
/range. Please see the Command Line Switches chapter in the
online manual.