I have two Security groups that I'd like to find out what it's being used for.  Is there a command or something that will display this?  

Thanks. 

No, check who is a member of it. It can be assigned to GPO, but not user share and such.

If you see no member of the group, desactive it and watch if someone call-in for a problem (it's the safier path to go)

Hi,

I agree with Yagmoth555. We can display nested AD security groups and group members.

In addition, please refer to the following articles and get detailed operations of displaying nested AD security groups and listing group members via script.

Display Nested AD Security Groups

http://gallery.technet.microsoft.com/scriptcenter/Display-Nested-AD-Security-abeb629f

List Group Members in Active Directory

http://gallery.technet.microsoft.com/scriptcenter/dcc9432e-d541-4be2-a39c-637c8d4c9fd0

Hope this helps.

Best regards,

Justin Gu