Hi, Grasshopper!
When you are using the List Data task, if you place your cursor on a choice like "Subtotal of", if you look below the selection pane, in a gray rectangle, you should see this text:
Prints a subtotal whenever the value of the specified variable changes or when the next BY group begins. The variable that you assign to this role must also be a variable in the Group analysis by role. You can assign a maximum of one variable to this role.
You can do this for every role to see what each one does. Otherwise, you can also look up the documentation for PROC PRINT in the SAS on-line documentation, since the LIST Data task is generating PROC PRINT code behind the scenes.
So, for your output, I would suggest that you
1) put Company Code (or Company Name) in the Subtotal Of role. (You should notice that when you put Company Code in the Subtotal Of role, then that choice makes it also appear in the Group By role.)
2) put Supplier Code (or Supplier Name) in the Group By role.
3) put Invoice Quantity and Invoice Value in the Total Of role
4) put the rest of the variables you want to see in the List Variables role (put them in the order you want to see them on the screen)
I would not worry about Identifying Label role right now until after you see whether these role choices will give you the kind of output you want. I suspect, that if you want to customize the break lines for subtotals and totals, you might want to consider moving to the use of PROC REPORT, which allows you to put customized text on the break lines and generally gives you greater control on which variables to use at the break.
Anyway, get your List Data task working first -- then you can play with Identifying Label. Also, if you put Supplier Code and Supplier Name in the Group By Role, then you will get one summary line for Supplier Code and a second summary line for Supplier Name. This is probably NOT what you want.
For more help with the List Data task or with using PROC REPORT as an alternative, you might consider contacting Tech Support.
cynthia