I tried to search related information in regard to the issue of "How to do tag-derivative-searches on Joplin Android app", I can only find one thread "On Android app, How to GoToAnything search?" and that one thread is now locked from adding new reply, so I have to inquire in this new thread and I quote:
Can someone share a more specific explanation about above quoted information？ An example of a real-world search session would be even better, I really could not follow what it meant, I tried a few guesses, and they all failed.
What is a GTA search? I googled it and did not find useful information, I would appreciate if some knower here could shed some light on it.
I have hundreds of tags in my Joplin app, if I want to locate the notes under one specific tag in my Android Joplin, I presently need to scroll a long way to locate specific tag (depends on its initial alphabet, sometimes it can be very long down below), is there a easier way for this task? I would appreciate it if someone can shed some light about this.
This suggests scrolling the tag list (you have tried that)
or the tag search with a wildcard tag:ap*
In that post the author mentions doing a tag search tag: and as they type, say "ap" they would like to see all the tags that start with "ap", like when doing a Go To Anything search for a tag on the desktop client.
The suggestion is that by using a wild card (*) a tag search can be undertaken that will show all notes which have a tag starting "ap" by using tag:ap*. Not quite the same thing but it was just a suggestion.
In the post you linked to the author mentions a "Go To Anything" search. They then refer to it as GTA. The reply also seems to be referring to "Go To Anything" as GTA.
If you know the name of the specific tag, say "elephant" you can search for notes with that tag by using tag:elephant as the search term and avoid the tag list completely.