Per IFRS, a "defined benefit obligation" (DBO) for accounting purposes:

is the present value of vested and non-vested benefits earned to the statement of financial position date, with the benefits measured using employees current salary levels.

is the present value of vested benefits only earned to the statement of financial position date, with the benefits measured using employees future salary levels.

is the present value of non-vested benefits only earned to the statement of financial position date, with the benefits measured using employees future salary levels.

is the present value of vested and non-vested benefits earned to the statement of financial position date, with the benefits measured using employees future salary levels.