Can a collateral challenge be mounted in the same court?

IN Public Prosecutor v Dato’ Sri Mohd Najib bin Hj Abd Razak [2019] 4 MLJ 421, the appellant (Public Prosecutor) appealed against the decision of the Court of Appeal (COA) to grant a stay of the respondent’s (Najib) criminal trial for seven offences in the High Court pending the disposal of his appeal to the Federal Court against the COA’s decision on three pre-trial criminal applications he had made.