Parents holding Vanuatu Green Card can apply for Hong Kong immigration. After obtaining a temporary residence card, they can apply for multiple visas to Hong Kong for one year.

The temporary resident card you mentioned should be a Hong Kong identity card, but it is not a permanent resident of Hong Kong, but it has the legal right of abode in Hong Kong. In this case, you can apply for going to Hong Kong once or more every three months, but you can't apply for more than one year.

The details are as follows:

Once or more every three months:

Visiting spouses, parents or spouses' parents, children or children's spouses can issue endorsements once every three months, or multiple endorsements every three months.

Many times a year:

Applicants who are reunited with couples whose spouses have minor children in Hong Kong may apply for multiple endorsements in Hong Kong.

When applying for visiting relatives endorsement for the first time, the applicant and the relatives to be interviewed must go to the exit-entry administration department of public security for interviews and inquiries.

I hope the above answers can help you.