As the Deputy will be aware, the Public Appointment Service (PAS) is the independent recruiter for the civil service.
I understand from PAS that an open Third Secretary competition was held in 2018 and 30 people were assigned from the panel to the end of February 2019. As part of ongoing workforce planning the question of holding a further open Third Secretary competition in 2019 will be considered. Third Secretaries are only recruited through open competitions.
PAS are in the process of completing an interdepartmental HEO competition which is open to civil servants only and which closed on 24 March 2019. Panels from such competitions, depending on the demand for staff, may be in place for 18 months to 2 years.
Individual departments and offices may of course recruit HEOs internally but this is a matter for individual departments having regard to their delegated sanction regarding staff numbers and sequences that apply for HEO competitions.