When you are working in a hierarchical design, there are two commands you can use to view the contents of a lower levels design.   You can open the subcircuit contents in a new window or you can open the subcircuit contents in the same window in which you are currently working.   Both commands are available by selecting a subcircuit and right clicking with the mouse.

The Edit Subcircuit command will push into the subcircut in the same window.    The View Referenced Doc command will open the contents of the subcircuit in a new window. 

Short Cuts

To make these command even more convenient you can use:

• Shift + double click = Edit Subcircuit
• Ctrl + double click = View Referenced doc