Conditional lookup values from multiple columns in related/lookup table.

Hi, vanonyuo 

Based on your description, I created data to reproduce your scenario. The pbix file is attached in the end.

Table1:

Table2:

There is a relationship between two tables. You may create a calculated column or a measure as below.

Calculated column:
Column = 
IF(
    Table1[Number]>0&&Table1[Number]<4,
    RELATED(Table2[Column1]),
    IF(
        Table1[Number]>=4&&Table1[Number]<=7,
        RELATED(Table2[Column2]),
        IF(
            Table1[Number]>7,
            RELATED(Table2[Column3])
        )
    )
)

Measure:
Measure = 
var tab = 
ADDCOLUMNS(
    Table1,
    "Result",
    var _number = [Number]
    return
    IF(
        _number>0&&_number<4,
        LOOKUPVALUE(Table2[Column1],Table2[Number],_number),
        IF(
            _number>=4&&_number<=7,
            LOOKUPVALUE(Table2[Column2],Table2[Number],_number),
            IF(
                _number>7,
                LOOKUPVALUE(Table2[Column3],Table2[Number],_number)
            )
        )
    )
)
return
SUMX(
    tab,
    [Result]
)

Result:

Best Regards

Allan

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.