fellow employees; co-workers
Refers to employees of the same company in relation to each other. Often used when talking about interactions, relationships, or mutual actions among colleagues.
Communication among fellow employees is important.
There is a culture of helping each other among co-workers.
同僚 is a general term for a colleague or co-worker, not necessarily emphasizing the mutual relationship. 社員同士 specifically highlights the reciprocal nature among employees of the same company.
Compound of 社員 (employee) and 同士 (mutual, fellow). The combination straightforwardly means 'fellow employees' or 'co-workers among themselves'.