Several global variables can be accessed in a process flow. How this is done is not documented well. In the example below I have created two variables and assigned them values of the global variables Audit_ID and Number_of_Errors.
Deploy process flow and execute. After execution the Output Parameters will have the values for the audit_id and the number_of_errors global variables. The variables could be assigned to output parameters of the process flow, input parameters to transformations, mappings or other process flows etc.