If you want it to be the default behavior of the Find Widget, you can set editor.find.autoFindInSelection to always, or to multiline, if you want it to be run on selected text only when multiple lines of content are selected.
If you want it to be the default behavior of the Find Widget, you can set editor.find.autoFindInSelection to always, or to multiline, if you want it to be run on selected text only when multiple lines of content are selected.