Try this:
get-adgroupmember |
Select-Object Name |
Export-Csv -Path <path-name-here> -NoTypeInformation
If you want other properties from the results returned by the get-adgroupmember cmdlet, add them to the Select-Object parameter values (e.g. SamAccountName, SID, etc.).
If the group contains objects other than users (e.g., other groups or computers) you'll have to deal with that. The easiest way to limit the output to only users would be to use a Where-Object between the get-adgroupmember and select-object.
--- Rich Matheisen MCSE&I, Exchange Ex-MVP (16 years)