Follow the steps to Look under the S-Parameter Testbench block's mask,
Right-Click on S-Parameter Testbench Block -> Locked Library Link -> Go To Library Block -> Right-Click on S-Parameter Testbench Block on the Library -> Look under Mask
While using multiple S-Parameter Testbench blocks in the same level of a model, there are multiple Terminate Function blocks in the same hierarchy, which causes a redundancy issue.
To solve this issue, the S-Parameter Testbenches can be grouped separately as atomic subsystems (one Block per Subsystem) which will resolve the redundancy.
To Group as an Atomic Subsystems,
Select all the blocks which are to be grouped > Right-Click > Create Subsystem from Selection > Right-Click on the newly created Subsystem > Block Parameters > Check the Checkbox on Treat as Atomic Unit.