Here is a way to extract all the necessary info from your XML using XML::LibXML and simple xpath queries. You will probably want to save the results to a data structure (an array of hashes should work) rather than printing them out like I do, but printing them out first allows you to see if it is working correctly.

See XML::LibXML::Node and XML::LibXML::Element for more details.

use XML::LibXML;

my $doc = XML::LibXML->load_xml(location => '/path/to/file.xml');

my @envdetails = $doc->findnodes('//ENVDETAILS');

for my $envdetail (@envdetails) {
    my $id = $envdetail->getAttribute('id');
    print "id: $id\n";
    my $dmgrhost = $envdetail->findvalue('DMGRHOST');
    print "DMGRHOST: $dmgrhost\n";
    my @nodes = $envdetail->findnodes('NODE');
    for my $node (@nodes) {
        my $nodeid = $node->getAttribute('nodeid');
        print "nodeid: $nodeid\n";
        my $nodehost = $node->findvalue('NODEHOST');
        print "NODEHOST: $nodehost\n";
        my @jvms = $node->findnodes('JVM');
        for my $jvm (@jvms) {
            my $jvmtype = $jvm->getAttribute('jvmtype');
            if ($jvmtype eq 'api') {
                my @jvmnames = $jvm->findnodes('JVMNAME');
                for my $jvmname (@jvmnames) {
                    my $name = $jvmname->textContent;
                    print "JVMNAME: $name\n";
                }
            }
        }
    }
}

# OUTPUT

id: abc
DMGRHOST: a.b.c.d
nodeid: 1
NODEHOST: v.x.y.z
JVMNAME: abc_api1.1
JVMNAME: abc_api1.2
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