For defining hierarchy, the steps shown below has to be followed
1. Create a main symbol (ex: a block with 2 input nodes and 1 output node) in the
Schematic page of circuit MAINHEIR
2. Draw the internal circuit (the internal schematic) within the new schematic page in the newly created circuit within the same project. Say the name of the new circuit is INTERNAL_CKT.
3. The sub circuit I/O nodes for the nets (the name of the nets in the main circuit and in the internal circuit has to be the same) in the internal circuit can be set next. For this load the internal circuit schematic and set the sub circuit I/O nodes for the nets for which u want to set the sub circuit tags.
Save this project as circuit file. This can be done from Circuit → Save Circuit.
This can be accomplished from Tools → Components → Hierarchy down → Set sub circuit I/O
Nodes → Give a suitable name as “Sub circuit name” with description. Then select Net → Click “Add”. Node description can be given to each of the nodes. → Accept
4. Now click on any of the node in sub circuit schematic and enable Tools → Components → Hierarchy Down → Hierarchy up (F1). The hookups will appear automatically