Untitled

Montant HT EUR =
IF (
    '01 ENCOURS'[Facture] = "X",
    IF (
        '01 ENCOURS'[Devise] <> "",
        '01 ENCOURS'[Montant HT]
            / RELATED ( Taux[Taux Budget] ),
        '01 ENCOURS'[Montant HT]
    ),
    IF (
        '01 ENCOURS'[Devise] <> "",
        '01 ENCOURS'[Montant HT]
            / RELATED ( Taux[Taux Budget] ) * -1,
        '01 ENCOURS'[Montant HT] * -1
    )
)