Search within selection

I am organizing a large workshop including SWOT analysis on many different topics in one board. After that workshop (which is where I am now) I’m analysing and reorganizing all of these notes to find overarching topics. IThe search tools and the possibility to search and select on the whole board is great, but in my work here, it would be a fantastic help to be able to select (drag and select) an area on the board, and then limit the search to that selection. That would make it possible to look for notes talking about a specific topic within the grouping that I’m working on - even to search for that and color the notes in a specific way or tag them to get both the focussed view and an overview. 

So please: make it possible to do exactly the kind of search that is now very strong, but to choose “full board” or “within selection”