Write logic for Calculated Column or Measure

1) EntryInERP

Create this calculated column in LessonLearned:

EntryInERP =
VAR HasStatus =
    CALCULATE (
        COUNTROWS ( 'Lesson Learned Status' ),
        'Lesson Learned Status'[LLID] = LessonLearned[LLID]
    ) > 0
RETURN
IF (
    LessonLearned[Milestone] IN { "M4", "M5" } && HasStatus,
    "Yes",
    BLANK ()
)

2) Open Ageing

Open Ageing =
VAR State =
    LOOKUPVALUE (
        'Lesson Learned Status'[CurrentState],
        'Lesson Learned Status'[LLID], LessonLearned[LLID]
    )
VAR DueDate =
    LOOKUPVALUE (
        'Lesson Learned Status'[DueDate],
        'Lesson Learned Status'[LLID], LessonLearned[LLID]
    )
VAR LastUpdate =
    LOOKUPVALUE (
        'Lesson Learned Status'[LastUpdate],
        'Lesson Learned Status'[LLID], LessonLearned[LLID]
    )
VAR Days =
    IF ( State = "WIP" && NOT ISBLANK ( DueDate ) && NOT ISBLANK ( LastUpdate ),
        DATEDIFF ( LastUpdate, DueDate, DAY )
    )
RETURN
IF ( NOT ISBLANK ( Days ), Days & " days" )