Remove All Filters but Specify New Filter

Try this. I used the logic I gave for the total, then used a slight different logic for the current total used as the numerator.

Type A Total =
VAR varTypeATotal =
    SUMX(
        FILTER(
            ALL( 'Data Table' ),
            'Data Table'[Type] = "A"
        ),
        'Data Table'[Total]
    )
VAR varCurrentTotal =
    SUMX(
        FILTER(
            'Data Table',
            'Data Table'[Type] = "A"
        ),
        'Data Table'[Total]
    )
VAR varPercentOfTotal =
    DIVIDE(varCurrentTotal, varTypeATotal, 0)
RETURN
    varPercentOfTotal