You can make the parameter file as a global parameter file by right clicking on parameter file and selecting the "set as global parameter file" option. You can use this global parameter file in all the projects within the workspace.
We can also include parameters of different parameter file located in different projects into one parameter file list. For this go to "Include" tab and specify the parameter file path of whose parameters you want to include in your parameter list and enable the check box "Show the parameters that will be used in the execution" in parameters tab of the same parameter file.