Changing a post's title will not remove it as approver. The post will still be set as approver as it was previous to the change of title, but it will be named differently, which may cause confusion.
For example:
Let's say John Smith is in a post called HR Manager, which is set as the approver for several other posts in the system. The reporting structure will show that the HR Manager is their approver.
When you change John's post's title from HR Manager to HR Director, the reporting structure will change to show that the approver for the posts is now the HR Director post. This is still the same post as before, but with a changed name, and John is still set as the approver.
If this is incorrect, it's possible you may have needed to transfer John from the HR Manager post to the HR Director post instead of changing the job title. This should have been done by following the steps in our article on changing an employee's post.
Moving John from the post of HR Manager to that of HR Director will ensure that the reporting structure will show the approver as the HR Manager and that whoever is next employed in the HR Manager post will now be the approver.