Postings between units, and locations is typically controlled by appropriate career manager. Your best option is to ensure that your chain of command is aware of your desire for a posting, that you ensure that your posting preferences are communicated to your career manager, and there needs to be a spot at the new unit in your trade and at your rank. In addition, you must realize that despite your desire, it may take a great deal of time before your goal is achieved.
Advice about my first posting. [Merged]
Memorandum for Posting request
OP: "I am re joining the Forces! I am working on a memo to request a specific posting to stay close to my children for my first posting."