Arcana domain Clerics get a Channel Divinity option called Arcane Abjuration. Here's the relevant part of the description:
After you reach 5th level, when a creature fails its saving throw against your Arcane Abjuration feature, the creature is banished for 1 minute (as in the banishment spell, no concentration required) if it isn't on its plane of origin and its challenge rating is at or below a certain threshold, as shown on the Arcane Banishment table.
The spell description for banishment says:
If the target is native to a different plane of existence than the one you're on, the target is banished with a faint popping noise, returning to its home plane. If the spell ends before 1 minute has passed, the target reappears in the space it left or in the nearest unoccupied space if that space is occupied. Otherwise, the target doesn't return.
It sounds like a creature below the CR threshold for Arcane Banishment is permanently returned to their home plane. However, the phrasing "banished for 1 minute" could be interpreted to say that after one minute they return.
Are creatures banished by Arcane Abjuration sent back to their home plane permanently, or only for one minute?