I'm a new user of Multisim. I've a silly question to most of you, how do I connect different schematics in Multisim and run a under one simulation?
For example, if I have my bandpass filter on one page and my amplifier on the next page. I've tried google but without much success.
You can use a Multi-Page design approach which is good for flat designs. In Multisim go to Place>>Multi-Page. To connect different pages use Off-Page Connectors (Place>>Connectors).
Now, if you are interested in reusing circuits I recommend you to use Hierarchical Blocks. Here is a good tutorial:
Repeating Common Circuits in NI Multisim: Hierarchical Blocks