I have got 2 files. Let us call them md5s1.txt and md5s2.txt. Both contain the output of a
find -type f -print0 | xargs -0 md5sum | sort > md5s.txt
Easy starter:
diff <(cut -d' ' -f1 md5s1.txt) <(cut -d' ' -f1 md5s2.txt)
Also, consider just
diff -EwburqN folder1/ folder2/