There is a search bar up the top - it will show you which category it is under.
Also if you have any specific GMIC questions there is a board for GMIC under the parent Gimp scripts and plugins.
Looks like it is under Testing - Naggabot - Artistic in 3.5.3. Same in 3.5.4
If you're looking in the online version you probably wont find it. There is about two hundred more filters in the downloaded version
https://gmic.eu/download.htmlAlso if you use it often, save it to your favorites! Just tested and yes you can save a testing filter.
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