[support] List brother/sister node

Hi list, I want to have a block that list sister or brother node's title of the current node. I use Taxonomy for each node. I have 3 level: Level1 Level1.1 Level1.1.1 Level1.1.2 Level1.2 Level1.2.1 Level1.2.2 Level2 Level2.1 ... When I display a node of Level1.1.1 I want to have a block with all Level1.1.1 node's titles. Which module I must use ? And how to config it. I'm trying Views and Panels, but I don't find the good settings. Thanks in advance for your help and to put me in the good way. Regards, Ceooph