Sorry for not being clear.
In your original post you stated
"i have done this using the filter fields and select the "between to" in dates and the "is one of" for product".
I assumed you had done this using the crystal select expert but you may have done this in a view that is feeding into crystal. I mention this becasue if you are using a view that pre-filters the data you need to remove those filters to give your boss the full scope of data to choose from.
OK. In Crystal there is a Select Expert. It is teh button of the hand grabbing a red ball.
Click on it.
Assuming you do not have any existing select statement at all it will open blank.
Click on New.
Select the Date field from the fields list and hit OK
Change criteria to 'Is between'.
Click on the first seelct option (this takes a little while to load as it is reading all of your data). Select the {?Begin Date} (this will be the name of the parameter you created). This will only appear here if the parameter data type matches the data type of the field you are filtering on (e.g. text to text, date to date, datetime to datetime, etc.). Seect the second option as {?Date End}.
Click OK.
Repeat the process but use the field of the product name.
Set it as "is equal to" and select the {?Product Selection}. Do not use in the list here. The Data pulled from the multiple selection process is an array that will be applied to the is equal to for each array option.
Hit OK.
Click back on the Select Expert Button.
Click on SHow Formula.
THis is where crystal used the GUI process I just walked you through to build the actual statement. It will be something like what I originally posted...
{table.Datefield} in {?BeginDate} to {?EndDate}
and {table.product_description_field}={?Product Selection}
If you click on the formula Editor button this is where you can just write (or edit) the select statement instead of using the GUI process from above.