Exegesis:

epignous ‘when he learned,’ ‘when he discovered.’

hoti ek tēs exousias Hērōdou estin ‘that he was from the region ruled by Herod.’ exousia lit. ‘authority,’ means here, ‘area, or region of rule,’ cf. on 4.6.

anepempsen auton pros Hērōdēn ‘he sent him up to Herod.’

anapempō ‘to send up,’ to a higher authority, ‘to send on,’ to the proper authority (here), or ‘to send back’ (vv. 11 and 15).

onta kai auton en Hierosolumois ‘who himself was also in Jerusalem,’ going with Hērōdēn, implying that for Pilate too Jerusalem was not his customary place of residence.

en tautais tais hēmerais ‘in those days,’ best understood as referring to the time of the feast.

Translation:

For learned see on 7.37.

He belonged to Herod’s jurisdiction, or, ‘he was from the country that was ruled by H.’ (Shona 1963), ‘he had come from where H. was the ruler’ (Tzeltal), ‘Jesus was-subject to (lit. was-governed by) H.’ (Balinese), ‘he was a person of H.’s area of responsibility (lit. watched place)’ (Ekari), ‘he originated from H.’s holding’ (Fulah).

Sent him over to Herod, preferably, ‘sent him on to H.,’ ‘sent him to his presence’ (Tzeltal), ‘had him taken to have his case heard by H.’ (Shona 1966), ‘ordered to bring him to H.’ (cf. Toraja-Sa’dan).

Who was himself in Jerusalem, or, since it gives the reason of what precedes, ‘for Herod was himself also/likewise staying in Jerusalem.’

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.