May 6 (Reuters) - U.S. retail chain At Home Group Inc said on Thursday Hellman & Friedman would buy the company in a deal valued at $2.8 billion, as the private equity firm looks to cash in on booming demand for home decor and home-furnishing products during the COVID-19 pandemic. (Reporting by Praveen Paramasivam in Bengaluru) Our Standards: The Thomson Reuters Trust Principles.