Make a boost filtered_graph by vertex label property

Currently, I have a graph, that I keep tracking of vertices and labels by means of an external map. So anytime I need to access the label property, I find the label in the map and get the mapped vertex.

/// vertex properties
struct VertexData
{
    std::string label;
    int num;
};

/// edges properties
struct EdgeData
{
    std::string edge_name;
    double edge_confidence;
};

/// define the boost-graph
typedef boost::adjacency_list<boost::vecS, boost::vecS,
        boost::bidirectionalS,
        boost::property<boost::edge_index_t , size_t , VertexData>,
        boost::property<boost::edge_weight_t, double, EdgeData> > Graph;

/// define vertexMap
std::map<std::string, vertex_t> vertexMap;

///loop through the vertices to make the vertexMap here ...
vertexMap.insert(std::pair<std::string, vertex_t> (label, v));

/// find any label in the map and access the corresponding vertex
vertex_t vertex = vertexMap.find(label)->second;

Now my question is: If I want to make a filtered_graph from current graph by filtering some labels, how should I do that in the class template? The examples in the boost graph library are different, and I checked also this post boost graph copy and removing vertex but it's quite different from what I want to do.

Thanks for any help.