In Pega 7, “Allow auto-process” option for Assignment shape has been introduced to allow the assignment automatically follow the path and flow action of the first when condition that evaluates to true.
I have considered two connector flow actions to be called based on some conditions.
Here, is the flow diagram. (NB: I could not paste actual screen shot here.)
You can use the Required Conditions section available in the security tab of the flow action rule. This "Required Conditions" section allows to define a list When rules to make the flow action available or not to the operator.
If your scenario 1 and 2 are based on different types of user then you can control this by giving unique privileges to perform those actions and they will be filtered automatically at run time based on roles which have those privileges.
Otherwise you can use When rules in security tab to control the access based on scenarios.