Split comma separated values in column and add it in a new column

[Sushant1]

I have a table where I created a measure SourceOrderTag which can have 2 values as you can see in the table

The order of data coming in the column is not fix.

I want to take the Drop Order from both rows and put it in the Source column & DRTV - Warranty Replacement in Order_tag column

To do that I wrote this expression - 

case(when(count(split(${sourceordertag},",")) = 2,index(split(${sourceordertag},","),1)),null)

Using this expression the split is happening but its not exactly giving me the result I want.

Can anybody please help??