I presume you mean the B&W image at the very bottom of this page:
http://helpx.adobe.com/lightroom/help/enhanced-spot-removal.html
If so, to do something similar in PS, you can use the "find edges" or "find color edges" filters to produce a very similar guide.
However, to be honest, I find that I really don't like to use an automated technique like to find spots because it misses some, and finds too many false positives. I do dust spotting the old-fashioned way and just manually inspect the image.
Then, to quickly clean up a large number of similarly sized dust spots, I zero in on a typical spot that I want removed, run PS's "Dust and Scratches" (D&S) filter on a copy of the entire image, and adjust the two sliders for the least disruptive, most effective removal of that particular spot.
This typically corrupts the image too much, so I then put a black layer mask on the D&S layer, and simply paint white into the layer mask wherever I see a dust spot of that type that needs to be removed.
An even better variant of this technique is to make two copies of the image, and use the D&S on both. On one, concentrate only on bright spots, and adjust the filter's sliders to optimize this, and on the other, do the same, except for dark spots. Then set the blending mode of the 1st to darken, and the blending mode of the 2nd to lighten. Breaking it up this way allows you to use a much lighter touch on each, with less obvious retouching artifacts.
BTW, if the "spot" is more than several pixels in size, then the D&S filter is no longer that effective, so then I'll switch to PS's "spot healing brush", or, if even larger, the patch or content-aware fill tools.
HTH,
T
