The following explanation applies to both start action and return action.

When you select a start action and return action, you will be asked to to specify how many times this action should be done before starting the retention analysis. 

If you are selecting a single start action, then that action must be triggered as many times as you define your minimum count for the analysis to start. 

If you are selecting multiple start actions, the minimum count refers to the cumulative occurrences of any combination of the selected actions. For example, if two distinct actions are chosen, and the count is set as "at least 2 times," the results may include two occurrences of a single action or one occurrence of each individual action. This provides flexibility in how you define the start of the analysis based on user interactions.