Thanks for this suggestion. This search is using MongoDB full-text search which stems words but indeed do not support matching inside words (similar to most full-test search). It's not just the beginning though, you can match for parts of the URL hostname/path (most ponctuation acts as a separator like dot, slash, dash, ampersand, etc..). It also searches inside the the custom Alias field, the current error name and the 4 letters check tokens.

So if you're in need of a more custom filtered view, you can also use Aliases to group your checks by tags/projects for example, or you can use checks tokens to hardcode a specific list of checks and re-use/share this filter for later.

I hope this helps :) I'll keep this suggestion open though to gather interest. Maybe I'll end-up reverting to a simpler string include if people prefers.