If this is what you're looking for, just simply add a Brightness/Contrast filter with both brightness and contrast set to 0. Then change the blend mode of the filter to "Multiply". This will darken the image, hopefully in the way you want.
However, this is not the only way to darken the image. The same result can be achieved by applying other filters such as Levels (Ctrl + L) and Curves. Play around with the values until you get what you want.
I would play with the Shadows/Highlights dialog box under 'Image → Adjustments', which will basicly darken the whites, brighten the blacks and also tone down the contrast and can easily produce this look by dragging a few sliders around.