use strict;
use warnings;

my $data=<DATA>;#As only one line in the file...
my @member_nos = $data=~m/<member_id>(\d+)/g;
print join $/,@member_nos;
__DATA__
<member_id>60</member_id><a>a</a><b>b</b><member_id>74</member_id><member_id>83</member_id>