Create a new variable which contains the probabilities of respondents belonging to each class based on a MaxDiff latent class analysis output. You should select the output before running this script or in the Latent Class MaxDiff's object inspector click on SAVE VARIABLE(S) > Class Membership Probabilities.
Example
When ran from the menu the script produces both a variable set of the class membership probabilities for each respondent and each class as well as a SUMMARY table of the average probability for each class:
The Class Membership Probabilities button will only create the new variable set, which you can then drag to the page to create the summary table
Technical details
To assign the respondent to the class with the highest probability, click the Class Membership button or Marketing - MaxDiff - Save Variable(s) - Class Membership.