Based on a request, here is the details on how parameter can be enabled/disabled based another parameter value.
Below is the requirement
There are 2 valuesets parameter. If for parameter 1 user selects Yes then the other paramter should be enabled whereas if No is selected then the parameter should remain disabled. This can be achieved by using a hidden parameter as explained below.

Step1: Need 3 value sets for 3 parameter.
Value set1 = BOM_SRS_YES_NO (Oracle Defined)
Value Set2 = AMS_SRS_CHAR1 (Oracle Defined)
Value Set3 = SV_DEPENDENT_VS (User Defined)

Step2: Create Concurrent program as displayed in the screenshot below
Parameter1: Main Parameter

Parameter2: Hidden PArameter

Parameter3: Dependent Parameter

Step3: Assign concurrent program to a request group and test your program.