When you point to the node in a PMI Dimensions or Annotations collection on PathFinder, then:
Show All sets the display state of all of the dimension elements or all of the annotation elements to be visible in the graphics window. The element names and respective icons in that collection are displayed in full color on the PathFinder tab.
Hide All sets the display state of all of the dimension elements or all of the annotation elements to be invisible in the graphics window. The element names and respective icons in that collection are grayed out on the PathFinder tab.