Hi Brenden! thanks for your replly. i used your if condition and i fixed it. thanks. i set the path as follows
{% if(DocumentContext.CurrentDocument.NodeLevel == 3){DocumentContext.CurrentDocument.Parent.Parent.NodeAliasPath + "/%"}else{DocumentContext.CurrentDocumentParent.NodeAliasPath + "/%"} |(identity)GlobalAdministrator%}
thanks again
ramesh