Welcome to the Oracle Forums. This can be accomplished using the GO_BLOCK() or GO_ITEM() built-ins. If you want to go to the first navigable item in a block, use the GO_BLOCK('YOUR_BLOCK') built-in. If you want to go to a specific item in a block use the GO_ITEM('YOUR_BLOCK.YOUR_ITEM') built-in.
If this doesn't answer your question, please provide more information about what you are trying to do and also, please include your Forms version and a sample of any code you may have written.