I’m not sure I understand what you want to develop.
I would like to point to a sample that shows how you can create bookmarks via code, if this does not lead you to be able to develop your solution please elaborate on the question.
This sample shows you how you can create bookmarks. - https://doc.developer.milestonesys.com/html/index.html?base=samples/componentsamples/bookmarkcreator/readme.html&tree=tree_2.html
https://github.com/milestonesys
After the sample was made a new method has been introduced; there is now also methods in the REST API. There is no sample is showing the use but the documentation is found here.-
https://doc.developer.milestonesys.com/mipvmsapi/api/bookmarks-rest/v1/