Greetings,
Lets understand the fact, what makes a talent apply for a new job. A better pay, a different profile, a promotion, a change of place, a breather to the career and plainly market research.
The talent that joined your firm, have a view to its career-plan and growth. Please look into individual situations, as separate cases. You may not be able to stop everyone from leaving your firm. You need to ensure you remain, their best employer.
Counselling and an open discussion is the least you can offer. Changing situations including, job profile, salary, location , reporting and brand , remains the luxury to few.
These discussions would provide you more than one input for talent development. Please consider them as your own research beyond your role. Try and gain as much understanding and views you can through them. These inputs will help you hire people who are best aligned to the roles and keep them motivated for a longer period of time.
Wish you all the best !