Altium Designer: How to handle these type of Nets?
If the signals on the bus from Page 2 to Page 1 are same like signals from Page 1 to Page 3 (they should be if you named buses with same name), then you can connect Page 3 directly with Page 2. You don't need two ports on Page 1. If they are not same, then you should change name of the buses and ports on Page 1.
You also need to set hierarchical structure of your project if you are are planing to use Top sheet.