How to add a new componetGroup in the policies' .content.xml under crxde lite in AEM6.3?

Using AEM 6.3, want to add one more componentGroup in the components property so template author can see these new components. The file name is .content.xml under the /conf/myapp/settings/wcm/policies, but I don't know how to add the new componentGroup using crxde lite? 

Here is a piece of  .content.mxl file under the /settings/wcm/policies: 

<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:sling="http://sling.apache.org/jcr/sling/1.0" xmlns:cq="http://www.day.com/jcr/cq/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0" xmlns:nt="http://www.jcp.org/jcr/nt/1.0" xmlns:rep="internal"
    jcr:mixinTypes="[rep:AccessControllable]"
    jcr:primaryType="cq:Page">
    <rep:policy/>
    <wcm jcr:primaryType="nt:unstructured">
        <foundation jcr:primaryType="nt:unstructured">
            <components jcr:primaryType="nt:unstructured">
                <responsivegrid jcr:primaryType="nt:unstructured">
                    <myapp-default
                        jcr:description="Default policy for editable layout containers"
                        jcr:primaryType="nt:unstructured"
                        jcr:title="Nextgen Touch Default"
                        sling:resourceType="wcm/core/components/policy/policy"
                        components="[group:ACS Commons, group:Social,group:General]"
                        policyResourceType="wcm/foundation/components/responsivegrid">

Thanks