You can create shared parameters in the project environment or in the Family Editor. Shared parameters are saved in a text file; you can then place this file in a shared area on your network to allow others to access it.
Shared parameters are organized in groups that you create to assist with categorization. For example, you might create a group called electrical for specific electrical parameters or a hardware group for specific hardware parameters. You can create as many groups and parameters as desired.
Your session of Revit can reference only one shared parameter file at a time. If there are other shared parameters in a different file that you want in the active shared parameter file, you need to export the parameters to the active file.