In this paper, we investigate multi-granular spectrum selective switches-based elastic optical networks. We have proposed an efficient dynamic control algorithm for elastic optical networks that utilize an intra-node group routing node architecture based on multiple granular spectrum selective switches. The developed algorithm is able to effectively cope with the intra-node group routing limitation of the considered node architecture in the networks to dynamically provision elastic light-path services. Performance of the proposed dynamic network control algorithm is evaluated by employing numerical experiments. The obtained results demonstrated that our developed solution offers almost the same performance, in terms of accommodated traffic volume, under the same fiber configurations comparing to that of traditional elastic optical networks while offering a significant necessary hardware scale reduction.