Search by a vendor.
 

Hello,

I want to be able to search by a vendor on a guild store ?

You mean search by the character selling the items?
AFAIK this is not possible via the game nor addons.

AwesomeGuildStore local filter?
 

If the question is "can I search for items sold by a single player in a guild store?" then it should be possible to write an AwesomeGuildStore filter to do that.

I don't think anybody has published such a thing, though. Probably not enough demand to warrant all the hassle in publishing and supporting.

Even with an addon, it wouldn't do what he's thinking. It'd just filter each page down to (typically) 0 items until you eventually reach a page with an item from that person. Then it might take another 5 pages to find another one and so on.

It is not so bad as it was, though: now you can purchase any item you have seen, so an addon can continue to search and populate the list without losing access to older pages items. IDK if AGS has adapted to that new feature in ESO, but... nicer than it was, for sure. ::)