There is no one right way to handle job title changes on a resume. Each situation will depend on your individual circumstances, whether the change in title represents a promotion or increase in duties, or if it is simply a change in name only. You will need to decide if highlighting separate titles will benefit your job search or if consolidation of titles maximizes the impact of your resume.
Evaluate the job responsibilities you have held under each job title. Consider whether they justify being featured separately or if the duties are sufficiently similar to be categorized under one title.
Demonstrate career progression by highlighting each separate job title and the increased responsibilities that accompanied them, particularly if you have been with the same company for an extended period of time.
List all the titles together under one bullet point if space on your resume is limited, you have had numerous titles in a short amount of time, or if you have had several titles for the same job.
Research the job market and specific requirements for the position you're applying for. If experience in a certain job title is required -- and one of your job titles matches that requirement -- consider featuring that title prominently on your resume.