Note: 'Oneself' is a third person singular reflexive pronoun.
1.
A speaker or writer uses oneself as the object of a verb or preposition in a clause where 'oneself' meaning 'me' or 'any person in general' refers to the same person as the subject of the verb. (FORMAL)
To work one must have time to oneself.
PRON
2.
Oneself can be used as the object of a verb or preposition, when 'one' is not present but is understood to be the subject of the verb. (FORMAL)
The historic feeling of the town makes it a pleasant place to base oneself for summer vacations...
It's so easy to feel sorry for oneself...
PRON