Hey Vish,
as Paul clarified, no terminals means a single terminal that means its a single path. To satisfy your use case you need fine-grained control over your devices by introducing multi-terminal devices and use "paths" to enable it.. Here is a picture clarify that

The first pair is what you have today, notice that the index space it is a single terminal thus a single path.
The second pair is what you need, you need a device with 3 terminals (can work with two as well), connect the lines to the appropriate terminals/ports and then define what "paths" are enabled instead of using the network attribute "open" or a "close" you have finer control where you can say path A-B, B-C, A-C..(ALL). You can disable path B-C but allow A-C and A-B and so on..
read more about this topic here Terminals—ArcGIS Pro | Documentation