If you want to add multiple classes to the already created expression, you just have to add a space between the classes. For example:
if $dataView1/IsLive = true then 'restrict-simulation-click class-two' else ''
If you want to add more if/else expressions, you can add else if. For example:
if $dataView1/IsLive = true then 'restrict-simulation-click' else if $dataView1/IsLive = false 'class-name' else ''
Take a look at Dynamic class widget where a microflow/nanoflow can be called and string(class) can be returned
Hope it helps!!!