find vertically overlapped bounding boxes?

I want to extract vertically overlapped bounding boxes and connect them vertical line, attached image show the overlapped bounding box.

     I am using below code, Can any one help me regarding extracted vertically overlapped boxes.

   propied=regionprops(L,'Area','BoundingBox','MajorAxisLength');

    X=[];
    Y=[];

for n=1:size(propied,1)

rectangle('Position',propied(n).BoundingBox,'EdgeColor','r','LineWidth',1)

X =[X; propied(n).BoundingBox(1) propied(n).BoundingBox(3)+ propied(n).BoundingBox(1)];
Y =[Y; propied(n).BoundingBox(2) propied(n).BoundingBox(4)+propied(n).BoundingBox(2)];

end