You can tell NodeXL to create groups using the values in a column on the Vertices worksheet. For example, if your vertices represent people and you have a "Country" column on the Vertices worksheet, NodeXL can create a group for each country. Or if you have a "Salary" column that contains numbers, NodeXL can create a group for each salary range that you specify. Groups can also be created using a column that contains dates, times, or dates with times.
Note that some vertices might be left "ungrouped." If a cell in the vertex attribute column is empty, or its value doesn't fall within one of the ranges you specify, the vertex will not be put into a group.