The meter on the camera is next to the viewfinder, so it isn't affected by the filter and you have to use the compensation dial on the back. The filter factors are usually shown on the filters, for example, orange is around 4x. This would darken the image by 2 stops, so you would use +2 compensation on the dial (overexposure). The only exception to this is when you use the Bronica's polarizing filter with the small filter holder directly over the viewfinder.
35mm: Rollei 35 SE, Leica M4-P, Nikon FM2n
MF : Bronica RF645, Ercona II, Franka Solida IIIe