Fonts listed on one of the three tabs (Active, Browse and Groups) on the fonts pane, are all using the same filter. By default all TrueType fonts and OpenType fonts are shown. Change the filter through the Filter window available through View -> Filter.
This filter is very powerful, when you are looking for specific fonts in a large font list. In the tab caption you will see two values, one for the number of filtered fonts shown and the other is the total number of (unfiltered) fonts.
See also: