I have these two selections B and C which added together make one continuous space (image1 ). Is it possible having these two selections to create "invisible" borders (image2 - 2nr.) so if we blur shapes: A and B (image3) the effect of the blur doesnt cross these borders (image4 - 1nr.).
so if we created a selection from these blurred shapes it should look like this (image5)
and the final result should look like this (image6)
The most important thing is that the blur from the shape A doesnt cross the border (image2 - 2nr.) but ignores the borders (image2 - 3nr.)