programmatically you can do something like this
//IS CURRENT USER MEMBER OF THESE GROUPS
using (SPSite site = new SPSite(SHAREPOINT_SITE_URL_BASE))
{
using (SPWeb web = site.OpenWeb())
{
foreach (string groupName in
Enum.GetNames(typeof(WebConstants.SPGROUPS)))
{
SPGroup spGroup = web.Groups[groupName];
if (spGroup != null)
{
if (spGroup.ContainsCurrentUser)
{
SPUserGroupList.Add(groupName);
}
}
}
}
}