Yes, there is. After you have created your groups using one of the "Group by" items on the NodeXL, Analysis, Groups menu, do this:
1. Go to NodeXL, Analysis, Graph Metrics.
2. In the Graph Metrics dialog box, check "Group metrics."
3. Click Calculate Metrics.
The metrics for each group will appear on the Groups worksheet.
For more information on how the group metrics are calculated, click the appropriate Details link in the Graph Metrics dialog box.