How we cite our quotes:
He knows who tries it how cruel is sorrow,
a bitter companion, to the one who has few
concealers of secrets, beloved friends.
The exile-track claims him.
Instead of human friends, he has only sorrow to hang with. In earlier lines, the speaker lamented how he had no one with whom he could share his inmost thoughts. This description of friends as "concealers of secrets" gets at the idea that one of the most important things about friends is that you can share your thoughts them. The "exile-track" that claims the speaker connects the experience of exile to the lack of companions.