equivalent psp filter- maximum and minimum

[rich2005]

This is the correct section

Possibly this:

1) High Pass, much used for sharpening an image see: https://docs.gimp.org/en/gimp-filter-high-pass.html

2) Maximum and Minimum, a maybe since I do not use PS but..
Morphological Filters: Minimum and Maximum The most common morphological operations are minimum (also known as erosion) and maximum (dilation) filters.

So try: Filters -> Generic -> Erode or Filters -> Generic -> Dilate

3) Offset
So try: Layer -> Transform -> Offset