##tells python to run within a specific group
myGroup = nuke.toNode('Group1')
myGroup.begin()
for node in nuke.allNodes():
    if node.Class() == "Shuffle":
        node['selected'].setValue(True)

myGroup.end()

#or
for node in nuke.toNode('Group1').nodes():
    if node.Class() == "Shuffle":
        node['selected'].setValue(True)

#or
for node in nuke.allNodes(group = nuke.selectedNode()):
    if node.Class() == "Shuffle":
        node['disable'].setValue(True)

##print group name from inside group
group = '.'.join(nuke.thisNode().fullName().split('.')[:-1])
groupNode = nuke.toNode(group)
print (groupNode.name())

##run a script at the root level from within a group
with nuke.root():
    #put any script below here to run at root
    nuke.nodes.Blur()

##tells python to run within all groups and at the root level
shuffle_nodes = [node for node in nuke.allNodes(recurseGroups=True) if node.Class() == 'Shuffle']

for n in shuffle_nodes:
    if 'disable' in n.knobs():
        n['disable'].setValue(True)

##tells python to run within all groups and NOT at the root level
group_nodes = [node for node in nuke.allNodes() if node.Class() == 'Group']

for group in group_nodes:
    with group:
        shuffle_nodes = [node for node in nuke.allNodes(recurseGroups=True) if node.Class() == 'Shuffle']
        
        for n in shuffle_nodes:
            if 'disable' in n.knobs():
                n['disable'].setValue(True)