How to show the location of original file

The PDF properties do not show any details about the original file, and that's intentional (many creators of PDFs will not want their readers seeing where the file came from, as the folder tree may contain names that are confidential or even insulting!). You can manually attach additional metadata and include the origin path if you want to, but it won't be there automatically.

"Location" in the properties panel is simply the folder name where the PDF lives, so you can tell if you're looking at a version in some temporary folder or not (useful if you've opened it as an attachment or from a website).

dear UVSAR ,
thanks a lot for your answer.
but during my last job, i was CAD operator, our CAD team(5 members) produced a large amount of drawings for archive, every member have the authority to change these drawings, only our CAD team had AutoCAD software, so all the CAD files must be plotted into PDF format and put on our companie's server for going through by other departments, when a drawing need to be updated, and it did by other member of our team, how can i find the CAD file location, i went to the server, find the PDF file, use the properties-location. it's very good function, we all like it.

is it some other version or can be shown in some settings? thank you!

You would do this in AutoCAD, not in Adobe. You use a Plot Stamp. Set it up by going to Tools...Options...Plot and Publish...Plot Stamp Settings. If you select the checkbox "Drawing Name", this will include the path and drawing name. When you go to plot, however, you have to make sure the "Plot Stamp On" checkbox is checked.

dear Hotrod97z , thank you so much!
only AutoCAD has this function? how about Microsoft office, word, excel, etc. thanks again.

In some Microsoft Office releases, you can insert the path and file into the Header or Footer. I can only find a way to insert the filename, but not the path, in Excel 2000 without using VBA. I know in later versions of Excel the filename and path are an option in the Header/Footer dialog box.

MS Word (Office 98SE through 2007) -
Insert a field containing field name "FileName" with the "\p" switch.

Be well...