duplicate layer n resize little bit bigger put it around the part the original union. the parts n circle represented layers that covered original union.
merge layer n level color, make graphic like "M"
merge layer n make this layer BW opacity 50
step 3 of 6
background cover union wi stamp
adjust the brightness little darker
step 4 of 6
put original size of union n set layer opacity 50%
step 5 of 6
put the 'bubble' n adjust position. layer opacity 50%