Boardview file for an HP board on the R13 platform, revision B, stored in a 328 KB RAR archive; BDV in the name denotes the boardview format. It shows component placement, part designators and net connections, letting a technician locate test points and trace signals from a schematic onto the real PCB. Open it with a boardview viewer such as OpenBoardView, FlexBV or Boardviewer. Confirm the revision letter on the board matches B, since layouts can shift between revisions of the same platform.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @schematicslaptop. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.