Example of Dashboard report: Number of Members

<objectCollection xmlns="http://midpoint.evolveum.com/xml/ns/public/common/common-3"
                  xmlns:q="http://prism.evolveum.com/xml/ns/public/query-3"
                  xmlns:c="http://midpoint.evolveum.com/xml/ns/public/common/common-3"
                  xmlns:t="http://prism.evolveum.com/xml/ns/public/types-3"
                  oid="72b1f98e-f587-4b9f-b92b-72e251dbb255">
    <name>All roles</name>
    <type>RoleType</type>
</objectCollection>

<report xmlns="http://midpoint.evolveum.com/xml/ns/public/common/common-3"
        xmlns:c="http://midpoint.evolveum.com/xml/ns/public/common/common-3"
        xmlns:icfs="http://midpoint.evolveum.com/xml/ns/public/connector/icf-1/resource-schema-3"
        xmlns:org="http://midpoint.evolveum.com/xml/ns/public/common/org-3"
        xmlns:q="http://prism.evolveum.com/xml/ns/public/query-3"
        xmlns:ri="http://midpoint.evolveum.com/xml/ns/public/resource/instance-3"
        xmlns:t="http://prism.evolveum.com/xml/ns/public/types-3"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        oid="15aeaf18-e78a-4029-8a26-50976a17ffd7">
    <name>Roles and Members</name>
    <assignment>
        <targetRef oid="00000000-0000-0000-0000-000000000171" relation="org:default" type="c:ArchetypeType"/>
        <activation>
            <effectiveStatus>enabled</effectiveStatus>
        </activation>
    </assignment>
    <archetypeRef oid="00000000-0000-0000-0000-000000000171" relation="org:default" type="c:ArchetypeType"/>
    <roleMembershipRef oid="00000000-0000-0000-0000-000000000171" relation="org:default" type="c:ArchetypeType">
    </roleMembershipRef>
    <objectCollection>
        <collection>
            <baseCollectionRef>
                <collectionRef oid="72b1f98e-f587-4b9f-b92b-72e251dbb255" relation="org:default" type="c:ObjectCollectionType"/>
            </baseCollectionRef>
        </collection>
        <view>
            <column>
                <name>name</name>
                <path>c:name</path>
            </column>
            <column>
                <name>members</name>
                <display>
                    <label>Number of members</label>
                </display>
                <export>
                    <expression>
                        <script>
                            <code>
                                import com.evolveum.midpoint.prism.query.*
                                import com.evolveum.midpoint.xml.ns._public.common.common_3.*

                                query = prismContext.queryFor(UserType.class).item(AssignmentHolderType.F_ROLE_MEMBERSHIP_REF).ref(object.getOid()).build();
                                objects = midpoint.searchObjects(UserType.class, query)
                                return objects.size();
                            </code>
                        </script>
                    </expression>
                </export>
            </column>
            <type>c:RoleType</type>
        </view>
    </objectCollection>
</report>