Not so much a guide, but since no achievements in this game track.
From the main menu:
->Data viewer
->Campaign data
->Campaign records
->Accumulated data (total MRP shown)
Alternatively
From the main menu:
->Data viewer
->Multiplayer data
->Multiplayer records
->Accumulated data (total MRP shown)
As a side note, after reaching 50 matches in TDM and battle royal exactly (for 2 other achievements) my total multiplayer MRP was a combined total of 8,129,923.
Which represents a first time players MRP into the series for multiplayer.
Completing the entire campaign on normal difficulty earned me 4,834,200 MRP.
Anyone going for this achievement will have to recognise the grind.