If you tick the 'All fields' then the search can become really slow as it goes through all comment and documentation fields, etc. We recommend deselecting that box and trying to be as specific as possible in terms of where to search and what type of data (for instance only searching in the current projects and libraries and choose process or whatever you are searching for under 'Type' field instead of choosing 'All') - see the screenshot below. This will then usually speed things up. Also please make sure that you only select the libraries that you need under the Goal and Scope > Libraries as this will also influence the search.
On top of that, if you only want to search for processes, you can also tick 'Show as list' - this is often handier.
