Techniques for grouping virtual machine (VM) objects for networking and security services in a virtualized computing system are described. In one example embodiment, VM attributes and identity attributes are obtained from a virtual center and an identity server, respectively. One or more desired security groups are then formed based on security requirements of the virtualized computing system. A user defined dynamic expression is then associated with the one or more security groups. One or more expression attributes are then determined by evaluating the user defined dynamic expression using the obtained VM attributes and identity attributes. VM objects are then grouped based on the determined one or more expression attributes. The grouped VM objects are then associated with the created one or more security groups for providing the networking and security services.