If I read you description correctly you have a single column in which you may have either a 'Charge' or a 'Detail'. I presume that the words 'charge' and 'detail' are not used but some other description which indicate an association to a Charge or a Detail is used.
Do you have a way to tell whether what appears in the field is a Charge or a Detail? If so, how does that work?
Can you provide some examples?
Here's how I understand it so far.
You have a "Charge and Detail Charge" column which contians the values
TO the RIGHT is another column with a value.
The model picks both columns as fields meaning you end up with a field that contains the text "Charge" or "Detail Charge".
If that is the case then there are a number of ways you could consider defining the filter but the easiest might be:
The internal help file has filter usage examples for many of the Functions in the section entitled FUNCTION REFERENCE and you might find a few ways there from which you can pick the one that feels most comfortable. Have a look at the TRIM related functions as well - they can be particularly useful with unruly fields when using the LEFT() function and similar.