PREFIX schema:     <https://schema.org/>

CONSTRUCT
{
    GRAPH ?graph
    {
        ?employee schema:areaServed ?territory
    }
}
WHERE
{
    ?employee_territory <#employeeID> ?employeeID ;
        <#territoryID> ?territoryID .

    BIND(uri(concat(str($base), "employees/")) AS ?container)
    BIND(uri(concat(str(?container), encode_for_uri(?employeeID), "/")) AS ?graph)
    BIND(uri(concat(str(?graph), "#this")) AS ?employee)
    BIND(uri(concat(str($base), "territories/", encode_for_uri(?territoryID), "/#this")) AS ?territory)
}