To show a group of nodes which be hidden.
1. This feature can't support the 'exedit' feature, so please don't use this feature in edit mode.
2. If you hide or show the nodes, it will effect the 'isFirstNode' and 'isLastNode' attribute.
3. Please use zTree object to executing the method.
the array of the nodes which will be shown
Please ensure that this data object is an internal node data object in zTree.
no return value
var treeObj = $.fn.zTree.getZTreeObj("tree");
var nodes = treeObj.getNodesByParam("isHidden", true);
treeObj.showNodes(nodes);