Instead of having to press the search button each time, why not filter the entire list when a character is typed? The filtering could begin as soon as 2 or more characters are typed to save on the load. Navigation keys would work as normal in the list (pgup, pgdn etc).
Perhaps the same kind of box could be added to the workspace pane.
You could even put the matching sequence in bold, provided the panes allows formatting.

I want to create similar topic But used search and found this.
Search feature in code explorer and navigator is almost unusable. It's better to replace them with a filter, which will work after 1 second you end typing.
Filter will leave on panel only matches.