There are three possible actions

do not process

process and prune

process and do not prune

It seems to me that your cases are

/ root directory, do not prune

/var /usr/local an absolute path where the top level directory has a name beginning with a-z A-Z or _, prune

every thing else e.g. .ssh /.kde tmp ../etc /+share, ignore

if ( $fs eq '/' ) { # only if the root directory
    my_find( $fs, 0 );
}
elsif ( $fs =~ m|^/\w+| ) { # matches /var
    my_find( $fs, 1 );
}
else {
    # everything else which we ignore
    # /.ssh
    # tmp
    # working/data
    # /-etc
}

sub find_me {
    my @directory = shift;
    # play nicely with others
    local $File::Find::prune = shift;
    <snip>
}
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If these are not the cases that you want to match I strongly suggest that you think clearly about what you are trying to match. Are relative paths allowed? How about the tmp directory in your current working directory (no / in the path)? Is there a need to restrict directory names to beginning with word characters?

Note that I pass parameters to find_me() rather rely on global variables, find_me() can now be used from elsewhere in the program. Also I localize $File::Find::prune so that changes to File::Find within find_me() don't leak out into the rest of your program. If you don't do that you will have to remember to explicit reset $File::Find::prune before you use any Find::File function elsewhere (or spend hours debugging;).