BMB Group

Withanage began work in 2004 while he was in his mid-20s. In fact, Pengiran Anak Abdul 'Ali Yil-Kabier (referred to as Abdul Ali), a descendant of the Bruneian royal family, co-founded it and serves as its co-chair. "I played on a polo team with Prince Abdul Ali," Withanage recalls while discussing the origins of the BMB concept. It resulted in a small, newly established business that was exceptionally well-connected and youthful, much like its top management. Prince Abdul Ali continues to serve as co-chairman and helped. In an interview, Withanage said he never had a business relationship with Prince Jefri Bolkiah and that he still has a great respect and connection with the Bruneian royal family, even if he no longer represents them. The BMB Group was officially established in 2006 by members of governing families in Asia and the Gulf.

On 29 June 2006, the Ministry of Finance (MoF) said that it had not granted any licenses for any fund associated with BMB Capital or any bank with that name. Referring to news articles that appeared in the Borneo Bulletin on Tuesday, 27 June 2006, and Wednesday, 28 June 2006, the MoF wishes to clarify that the Ministry has not granted any licenses in relation to funds associated with BMB Capital, according to a press release sent to the publication.

The parent firm of BMB Capital Management provided clarification on the news reports about its Syariah funds through an authorised spokesman in a separate press release to the Borneo Bulletin. According to the spokesperson, BMB Capital is a limited liability partnership (LLP) incorporated in the Cayman Islands, and its general partner is BMB Capital Management, which is also registered there. The parent business said that all of the fund's current operations are being managed outside of Brunei. The parent company's representative informed the Bulletin that BMB is only registered as "BMB," despite the Middle East News Agency identifying BMB as Brunei Merchant Bank.

As of June 2009, BMB has refocused its operations to offer financing and specialised advice to Forbes 500 families alone. These include the transfer of leadership of BMB to Rahula Withanage, who would lead Scepter Partners alongside Anthony J. Steains and his previous Blackstone Asia Advisory Partners team, from former chairman and CEO Withanage.

BMB Group's position as investment manager for a philanthropic fund established in the spring of 2009 by the 56 member states of the Organisation of Islamic Cooperation (OIC) demonstrates the company's extensive and growing links at the top of eastern society. The group's capacity as the investment advisor for a fund formed by the OIC serves as a showcase. With a $3 billion fund, this program seeks to bring together affluent Islamic nations to aid underprivileged communities around the globe. Prince Abdul Ali and Withanage realised they could also invite supportive Middle Eastern royals to participate in the initiative and raised money from a variety of Asian royals. A site for Islamic-focused investment, particularly between Asia and the Middle East, gained traction.

A portion of Alliance Capital Group, a real estate company based in the Netherlands that oversees €3 billion ($3.67 billion) in properties across Europe, was purchased by BMB on 23 June 2010. The amount of the share that BMB was purchasing was not disclosed by the deal's executives, but the business claimed that $500 million was invested in Alliance Capital Group to establish the merged company, which would now be known as BMB Alliance.

As an investor in BMB, Withanage will continue to play a significant role in the company's development even if it is no longer a member of the management team as of 2 October 2015. Scepter has given BMB Group a $2 billion commitment to create and run business ventures that have the potential to significantly impact and change the lives of Forbes 500 families. Prince Abdul Ali stated that, "We hope that some of BMB's activities may generate investment opportunities for Scepter as a co-investor in the future." When significant obligations might be necessary, Scepter aims to have a positive working relationship with BMB." Withanage was succeeded as CEO of BMB by Rahula Withanage.

In 2017, BMB ceased revealing the extent of its advisory engagements at the request of its investors. BMB does not take in any money from other sources and exclusively publishes accounts for its investors. The intention was to highlight companies that have been founded to deal with some of the most urgent issues the world is now experiencing. Scepter will carry on as a family office while generating significant money and influence for its patrons. In order to take on the role of CEO of Philantech, which is now creating revolutionary venture philanthropy and sustainable development firms, Withanage officially left Scepter Partners and the BMB Group in 2018.