Perhaps the most common doublet of this kind is where one of the words is Malay and the other is English. For example, on page 2 of Media Permata of 14 April 2012, in quoting a member of the fire brigade who was discussing the reasons for the outbreak of a fire, we find the sentence:
Kabel sumbangan itu dipercayai terlibih bebanan atu overload.which might be translated as
The extension cabel is believed to be too much load or overload.In other words, terlibih beban and overload mean exactly the same thing, but one is Malay and the other is English. My assumption is that this is done because lots of people use the borrowed word overload even when speaking Malay, but the fire officer wanted to ensure that people who only speak Malay could also understand him.
This does not just happen in Brunei. On 15 April, I was listening to the news on Astro Awani (the Malaysian cable TV news channel), and I heard Dr Rais Yatim, the Malaysian Minister of Communications, mention 'facility atau kemudahan', when facility and kemudahan mean the same thing.
This raises a few questions: is the phenomenon equally common in Malaysia and Brunei? And is it more usual to put the Malay term first or second?
It is interesting that this type of doublet closely matches legal doublets found in English, such as 'aid and abet', 'goods and chattels', 'null and void', 'part and parcel' (see here), where the first word is Anglo-Saxon and the second is Latin or French; and the original rationale was to allow ordinary people in England to understand legal terminology. The only difference is that these English doublets have been in the language for centuries. Only time will tell whether the Malay doublets survive for as long.