>perl -wMstrict -le
"my $parent = qr{ \.\. / }xms;
 my $dir    = qr{ (?> [^/]+ /) (?<! $parent) }xms;
 print 'output:';
 for my $f (@ARGV) {
   1 while $f =~ s{ $dir $parent }{}xmsg;
   print $f
   }
"
/vobs/foo/../foo/bar/me/my/../../me/my/moo
/vobs/foo/../bar/me/my/../../ma/mo/moo
/vobs/x/y/z/../../../x/y/z/filename
/vobs/x/y/z/../../../a/b/c/filename
/a/../b/c/d/../../e/f/g/h/i/../../../j/k/l/m/n/o/p/../../../../q
output:
/vobs/foo/bar/me/my/moo
/vobs/bar/ma/mo/moo
/vobs/x/y/z/filename
/vobs/a/b/c/filename
/b/e/f/j/k/l/q