To limit the choice of events in Eventure online, you need to enable the Event group option. This helps to prevent participants to be able to book events that are held simultaneously (or to force a participant to choose at least one event).
To apply item settings to events go to the Module Content --> Registration Events and click on an event.
Step 1: Give all the events that are in the same group the same ID.
Step 2: Fill out the limit for the amount of events to choose from via Min and Max. Do this for every event with the same ID!
Step 3: Click on save settings.
Now the participant will not be able to select more than the given number of events in this group.
In this example, participants have to choose either Workshop A or Workshop B, or both (Event Group 1). They also have to choose either Workshop C or Workshop D, or both (Event Group 2).