Dear friend!
You can do it this way:
1. You need to select the Protection check box on the upper right corner of the Main Topology in advance.
2. Right-click in the main topology and choose Search SDH Protection Subnet. The Search Protection Subnet dialog box is displayed.

3. Set the search condition and enter the keyword. Click Search.
4. Double-click the protection subnet on the list. The protection subnet that is searched out is highlighted in the Network View.
Thanks!