How to group the same fields in one column with limited access

[LearningasIgo2]

Hi, Im new to power BI and ive been tasked to migrate a tableau report 

In the tableau report, the purchased order number (i.e BEFA123456, BEFA6789, BEFA101112, BEFB131415) has been trimmed down using the formula = LEFT([PurchasedOrder Number],4) and is seen like so: 

Im trying to migrate this to power BI and i've managed to follow the formula by creating a new column (for some reason when using a measure the column is not recognised and ive done aggregate measure to solve this but its not coming through correctly.)

So at the moment I am stuck with this table in power BI but I was to group them as seen above:

Limitations I have:

- Unable to group them as we have around 10,000+ purchased order number (ive tried filtering it but it doesnt work when i add the other order number)

- when creating a new group i am limited to 10 groups.

- unable to use power query as its a semantic model - restricted by the company 

- unable to see this in a table format 

Any help would be greatly appreciated 

[lbendlin]

Are you able to create calculated columns?  If yes then create one that says LEFT([original column],4)  and add that new column to the visual. Don't add the original column (or put it in the hierarchy lower) if you want to group by the new column.  No need to manually create groups.