I apologize if this has already been answered; I tried doing a search, but did not get any straight answer. If this has been answered, please link the appropriate thread, or private message me with the link.

Thanks in advance.

Considering that they create a network where you can use supplies from one settlement at another without a direct connection, no. Supply lines work two ways.

Supply lines work both ways. As long as any two settlements are connected, they share the resources. So if A is connected to B and C is connected to B, then A, B and C all share the same total resource pool.

Furthermore, they don't have to be "hub and spoke" to get everything shared. They can be daisy-chained and supplies will be equally available everywhere.