Boardview for the H46Y board in a RAR archive of roughly 358 KB; BDV in the name stands for boardview. It opens in programs such as OpenBoardView or FlexBoardView depending on the internal format. The name gives no revision, so check the code and revision silkscreened on the PCB. Combined with the H46Y schematic, it lets a technician jump from a net on the diagram to the physical part, locate test points, measure rails and find which component is pulling a line to ground.
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 @cyberlanelectonik. 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.