redhat linux find perms + prune

I'm trying to find all files and dirs under an NFS Filer share where group doesn't have read and write. I have to exclude all instances of the backup dir .snapshot from the search

=Commands that work=

find /test/data -perm -g-r,-g-w | egrep -v -e '.snapshot' | xargs ls -l

find /test/data -perm -g-r,-g-w -exec ls -l {} \;

=Commands that don't work=

find /test/data  -name '\.snapshot'  -prune  -perm -g-r,-g-w | xargs ls -l 

(This command only looks at the .snapshot dir and runs the action on .snapshot

find /test/data  -path '\.snapshot'  -prune  -perm -g-r,-g-w | xargs ls -l

(This command lists the content of the users home dir which is a different path to which i'm searching)

The command that I can run does it with egrep but when it comes to executing the perms to make changes I want to be able to prune this dir out to save time since some of my filesystems are 500G

STRUCTURE OF DIR I'M GOING TO BE SEARCHING AND CHANGING.

/test/data

dir dir1

dir dir2

dir dir3

dir dir4

dir dir5

dir .snapshot

When it comes to changing the perms to 775 for instance I want to be able to run the command below but with -prune to save time when working on a 500G filesystem.

find /test/data -perm -g-r,-g-w -exec chmod 775 {} \;

I KNOW THIS WON'T WORK BASED ON FAILURE WITH THE FIND ABOVE WITH PRUNE 

find /test/data -name '\.snapshot'  -prune -perm -g-r,-g-w -exec ls -l {} \;

Thank you