An OxideMod python plugin that copies group permissions, literally a c+p from flamingmojo's blog: https://flamingmojo.wordpress.com/2016/07/15/making-a-plugin-starting-off/

groupCopy.py

import BasePlayer

class GroupCopy:
    def __init__(self):
        self.Title = "Group  Copyer"
        self.Author = "FlamingMojo"
        self.Version = V(1,0,0)
        self.HasConfig = False
 
    def Loaded(self):
        command.AddConsoleCommand('groupcopy.copy',self.Plugin,'Copy')
        command.AddChatCommand('copygroup',self.Plugin, 'Copychat')
        permission.RegisterPermission('groupcopy.allowed',self.Plugin)
 
    def Copychat(self,player,cmd,args):
        arglist = list(args)
        self.Copy(None,player,arglist)
 
    def Copy(self,args, callingply = None, argslist = None):
        if not callingply:
            callingplyID = str(args.connection).split('/')[1]
            for player in BasePlayer.activePlayerList:
                if player.UserIDString == callingplyID:
                    callingply = player
        if callingply.IsAdmin() or permission.UserHasGroup(callingply.UserIDString, 'admin') or permission.UserHasPermission(callingply.UserIDString, 'groupcopy.allowed'):
            if args:
                if len (args.ArgsStr.split(' ')) != 2:
                    print 'Needs 2 arguments, NO SPACES IN GROUP NAME'
                    return
                else:
                    startgroup = args.ArgsStr.split(' ')[0]
                    finishgroup = args.ArgsStr.split(' ')[1]
            elif argslist:
                if len(argslist) != 2:
                    print 'Needs 2 arguments, NO SPACES IN GROUP NAME'
                    return
                else:
                    startgroup = argslist[0]
                    finishgroup = argslist[1]
            else:
                print 'Invalid method call!'
                return
            if permission.GroupExists(startgroup):
                if not permission.GroupExists(finishgroup):
                    rust.RunServerCommand('group add %s'%finishgroup)
                    print 'Added group'
                permslist = permission.GetGroupPermissions(startgroup)
                for perm in list(permslist):
                    rust.RunServerCommand('grant group %s %s'%(finishgroup,perm))
                    print 'Granting %s Access to: %s' %(finishgroup, perm)
                print 'Done Copying'
            else:
                print 'Invalid start group'
                return