node js - get url params from original base url

In my node JS express app I have defined routes with path having regex expressions in my app.js file. i.e

var tableRoute = require('./routes/tables');
app.use('/keyspaces/(regex to match param)/tables',tableRoute);

Then in my routes/tables.js file I have following handler defined for this route

router.get('/', function(req, res, next) {
// need to access url param here
});

Now clearly I cannot access my url param via req.params.xzy because here handler is defined for '/' not for '/keyspaces/:xzy/tables', is there any way I can access this url param here from original base url.