Relative path or get the current working directory

It really strikes me as odd that this isn't possible but there needs to be a way of getting the current working directory or of using relative paths so that I can package up the PBIX and the data into a zip file and send this to a customer - its really important for my customer that the data is stored where they want to store it and that they have full control of it. I want to have the PBIX file and a folder containing all data in one location and the PBIX read the data local to it. The only way to do this at present is to set a parameter in the PBIX and tell the customer to set this to full path of the folder that contains the data. Ideally power bi would allow the use of relative paths and this would be simple or alternatively to find the path of the PBIX so that this could be used to work out the local path. As it stands, if the user does not set the parameter correctly and clicks refresh then the data will not be found.