Custom Fiscal Year error

arp2 - this will work for last week:

VAR LastWeekStart =
    SELECTEDVALUE ( FYCalendar[WeekStart] ) - 7
VAR LastWeekEnd =
    SELECTEDVALUE ( FYCalendar[WeekEnding] ) - 7
RETURN
    CALCULATE (
        DISTINCTCOUNT ( MasterProjListR02[Project Number] ),
        REMOVEFILTERS ( FYCalendar ),
        MasterProjListR02[Project Creation Date] >= LastWeekStart,
        MasterProjListR02[Project Creation Date] <= LastWeekEnd
    )

and your measure for YTD will already work:

see attached file

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