In addition to the very important general need for the ability to find and replace within the scope of a selection, a valuable feature for someone like me would be the ability to replace strings SEQUENTIALLY.
For example, I have coordinates that are all labeled β1-1β and I want them to range from β1-1β to β1-15β; right now, because I have HUNDREDS of layers that include the suffix β-1β I have to update each of those manually to β-2β, β-3β, β-4β., etc. within the scope of my selection.
If I could just select to replace and increment the β-1β part of each text field sequentially within my selection that would open up whole new worlds of efficiency for me.