I assume you mean dual nationality?
I have not heard of any applicants being granted Dual Citizenship yet. Dual Citizenship is not an automatic process and that an applicant must demonstrate the eligibility to be considered.
See C8 on the link - https://www.immigration.gov.pg/citizenship.html - to download an application form for Dual Citizenship.
The Government has approved new application fees for those applying for dual citizenship and at May 2017 the costs were:
K5, 000 - Current PNG citizen or former citizen seeking dual citizenship with a prescribed country;
K2, 000 – Children of mixed parentage turning 18 years old and intend to retain their PNG citizenship; and
K15, 000 – Citizen of a prescribed country seeking dual citizenship.
If you are aged 19 or older at the time of the application you must not hold Citizenship with another country at the time of application. You may only seek approval to obtain Dual Citizenship with an prescribed country where you do not already hold that other Citizenship. If you were PNG Citizen and obtained Citizenship with another country without Dual Citizenship approval and kept that other Citizenship past your 19th birthday, you will have automatically lost your PNG Citizenship. In this case you are a former PNG Citizen, and will need to apply for: resumption of your PNG Citizenship, or PNG Citizenship by Naturalisation (Long Term Resident, Investor or Sportsperson), or PNG Citizenship by Descent (parent/grandparent) or PNG Citizenship by Marriage.
At one stage PNG did not recognise dual nationality except for children under 19 years of age. This may limit the ability of the "other" Government to provide consular assistance to Papua New Guinean dual nationals who are arrested or detained however recently (2017) PNG enabled dual citizenship for certain individuals.