multi level sorting

OK, this can be done using a custom template, it’s not built in to the plugin. You’ll need some HTML and php skills, but it’s pretty simple, you just need to look at the sort control that is normally shown, then add another set of inputs for each level of sorting you need. Add [] to the name of the selector so the values of the inputs are submitted as an array.

Take a look at this for instructions on setting up custom templates:

Using Participants Database Custom Templates