Single channel vs Multiple channel-Hyperledger fabric supply chain

This depends on the use case you are trying to implement. If there is need for confidential transaction/ledger for some organizations in the n/w, separate channel will be required. You may also consider private data collection if the same ledger have to be used among participants, but some transaction data have to be kept confidential among them.

https://hyperledger-fabric.readthedocs.io/en/release-2.4/private-data/private-data.html#when-to-use-a-collection-within-a-channel-vs-a-separate-channel