There is a command to do an inventory search but it is a bit of a pain. You have to have the exact text and spelling of the item or you will get a "No results" message. So, you have to know if the item is spelled out in full or abbreviated. The command is:
/itemsearch "Blk. Tiger Fang"
Your search item must be in quotes. This isn't a very forgiving search. Sometimes it is just much easier to auto sort each bag and look in the area where you know the item you are looking for will sort to.
I've been playing 11 years so I just have a natural instinct as to where the items will sort to and I've developed a system that I'm religious about what items go in which inventory bag. My husband makes himself invisible IRL after he has played my character because he is afraid of me finding that he put gear or weapons in the wrong place...and he ALWAYS does!!! He knows I will swear under my breath and cuss him out. His system is "throw it in whatever bag" >.>