Hi Sindaiel,
You've had amazing cross-training opportunities with this employer! You can definitely use this to your advantage on your resume -- the ability to multitask is applicable to every industry, and also speaks to your flexibility and willingness to take on various responsibilities.
The best way to present the information on your resume depends on your career goal. The most effective strategy will be to emphasize the jobs, responsibilities, and accomplishments that are most relevant to your goal. So if you are targeting a position in training, you can bring that aspect of your work to the forefront and focus on your training job duties and accomplishments.
No matter what you emphasize, it's a good idea to have an introductory statement explaining your various roles (e.g., Entrusted by management to handle multiple roles and responsibilities including front-end manager, assistant department manager, etc).
You can also break your bulleted list of accomplishments into categories, like this:
Selected Accomplishments:* Recruitment & Training: List major accomplishments...
* Department Management: List major accomplishments...
* Front-End Management: List major accomplishments...
It's okay to go to two pages if necessary.
Here's an article that might be helpful:
One Employer, Multiple Jobs: How to Handle It on Your Resume