How to use setm in puppet

I would like to change a one property name ( "modcluster.proxylist" ) with setm Command in Puppet. My following code is not working. Any help is much appreciated.

    augeas { "jboss_domain_config":
            incl    =>      "/opt/domain.xml",
            lens    =>      "Xml.lns",
            context =>      "/files/opt/domain.xml",
            onlyif  =>      "match /files/opt/domain.xml/domain/server-groups/*/system-properties/*/#attribute/name modcluster.proxylist"
            changes =>      "setm /files/opt/domain.xml/domain/server-groups server-group[.]/system-properties/property[.]/#attribute/value kumaran",
    }

Following is my Source XML which i would like to change.

<server-group name="ServiceGroupOne" profile="full-ha">
    <system-properties>
            <property name="jboss.default.multicast.address" value="232.0.2.20" boot-time="true"/>
            <property name="modcluster.proxylist" value="192.168.79.77:7777" boot-time="true"/>
            <property name="modcluster.lbgroup" value="SearchGroupOne" boot-time="true"/>
    </system-properties>
</server-group>
<server-group name="ServiceGroupTwo" profile="full-ha">
    <system-properties>
            <property name="jboss.default.multicast.address" value="232.0.2.20" boot-time="true"/>
            <property name="modcluster.lbgroup" value="SearchGroupTwo" boot-time="true"/>
            <property name="modcluster.proxylist" value="192.168.79.77:7777" boot-time="true"/>
    </system-properties>
</server-group>
<server-group name="ServiceGroupThree" profile="full-ha">
    <system-properties>
            <property name="modcluster.lbgroup" value="CommonSearchGroup" boot-time="true"/>
            <property name="modcluster.proxylist" value="192.168.79.77:7777" boot-time="true"/>
            <property name="jboss.default.multicast.address" value="232.0.2.20" boot-time="true"/>
    </system-properties>
</server-group>

There's quite a few problems in there. Let's deal with them one by one:

it seems the domain.xml code you provide is wrong, as there's no domain and server-groups nodes as your Puppet code suggests. I take it there's two more levels around the code you provided:
```
<domain>
  <server-groups>
    
  <server-groups>
<domain>
```
there's no need to set context when using incl and lens, it's automatic
you misunderstood the way setm works: the first parameter is the nodeset on which Augeas will loop, the second one is the subnode to set and the third one the value
the change you want to do with setm is inherently idempotent, there's really no need to use onlyif here.

Here's the result:

augeas { "jboss_domain_config":
  incl    =>      "/tmp/domain.xml",
  lens    =>      "Xml.lns",
  changes =>      "setm domain/server-groups/server-group system-properties/property[#attribute/name='modcluster.proxylist']/#attribute/value kumaran",
 }