In Multisim you are able to easily organize a circuit by taking a modular design approach. Both subcircuits and hierarchical blocks take sections of a circuit and replace its representation on a design with a block. With a Hierarchical Block you can organize a design so that particular sections of a circuit (such as a filter or an amplifier) are represented with a block which internally contains the circuit. Each block is treated as a component with input and output pins. If the block is double-clicked upon, a schematic representing the internal circuitry can be viewed and edited.
For further details on how to create Hierarchical Blocks please refer to the tutorial Repeating Common Circuits in NI Multisim: Hierarchical Blocks