Running Total restart each year

To use this Time Intelligence function you need a proper Date table and reference the column that has marked as the date column (not possible with a column like you showed in your picture).

If you're not prepared to work with such a table, you'd have to add a year-filter into your original measure like so:

TRACKED_LOANS running total in Year Quarter =
CALCULATE(
    SUM('FACT_Unique Tracked Loans'[TRACKED_LOANS]),
    FILTER(
        ALLSELECTED('DIM_Date'[Year Quarter]),
        ISONORAFTER('DIM_Date'[Year Quarter], MAX('DIM_Date'[Year Quarter]), DESC)
    ),
    FILTER(
        ALL('DIM_Date'[Year]),
        'DIM_Date'[Year] = MAX('DIM_Date'[Year])
    )
)