@Pginer-WMF, here are some questions to help nail down this interface:

• If the desire is for this search to a) work x-wiki and to b) find both read and unread notifications, then do we need to include a wiki or language selector in the tool? E.g., something similar to the dropdown on the Wikipedia.com home page search, for example?
• Do we need to somehow let users know that this isn't a free-text search-- i.e., that they can't search for header or snippet text?
• If we include search by date, how will users know what date format to use? Will we include a date-range interface?
• If the search allows Boolean functions (see T132805), do we need to indicate that?

In T132804#2211050, @jmatazzoni wrote:

@Pginer-WMF, here are some questions to help nail down this interface:

• If the desire is for this search to a) work x-wiki and to b) find both read and unread notifications, then do we need to include a wiki or language selector in the tool? E.g., something similar to the dropdown on the Wikipedia.com home page search, for example?

The idea was for the filters to affect the search. So if the wiki selected in the filters is French Wikipedia, the user will be searching the notifications of that wiki. If we are able to provide filters that aggregate multiple wikis (e.g., "all contents" or "all my talk pages"), the search will cover more than one wiki.

• Do we need to somehow let users know that this isn't a free-text search-- i.e., that they can't search for header or snippet text?

As the search bar gets the input focus, we can use the auto-complete panel to surface options and guide the user selection. That includes assistance to indicate a date range or boolean operators.