Define test variants and associate them to the right Use-Cases.
Any part of your logic can be limited to only apply in a specific A/B testing variant. This means that (if you create 1 test variant) 50% of the visitors will get the control (all your logic Use-Cases except the ones which are connected to your test variant) and 50% will get your test variant (all your logic Use-Cases except the ones which are connected strictly to control or to other test variants).
...
Then select, duplicate or add the Use-Case(s) which should be tested, go to the Settings tab, and conect connect them to your new test variant.
...